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ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -1-PART 1:ROADWAY DEVELOPMENTSECTION 100: GENERAL INFORMATION101 PURPOSE100-1101.01 INTRODUCTION100-1102 CONTENTS AND ORGANIZATION100-1102.01 PART 1: ROADWAY DEVELOPMENT100-1102.02 PART 2: ROADWAY DESIGN100-2102.03 PART 3: STRUCTURES AND BRIDGES100-2103 TECHNICAL MEMORANDUMS100-2103.01 GENERAL100-2103.02 TECHNICAL MEMORANDUMS - GENERAL100-2103.03 TECHNICAL MEMORANDUMS - SPECIFIC100-3104 ROADWAY CLASSIFICATIONS100-3104.01 ROADWAY SYSTEM100-3104.02 DESIGN100-3104.03 CRITERIA FOR DESIGN CLASS DESIGNATION100-3105 ROUTE DESIGNATIONS100-5105.01 INTRODUCTION100-5105.02 ROUTE NUMBERS100-5105.03 ADDITIONS, DELETIONS, AND REVISIONS100-5SECTION 200: DESIGN CONCEPT DEVELOPMENT201 TRANSPORTATION PLANNING200-1201.01 INTRODUCTION200-1201.02 ROAD SECTION200-1201.03 TOWN PLANNING200-1201.04 MAPPING200-1201.04.01 General200-1201.04.02 Topographic Mapping200-2201.05 PROJECT LIMITS200-2201.06 PROJECT IDENTIFICATION AND NUMBERING200-6201.07 INTERDEPARTMENTAL COORDINATION200-6202 ENVIRONMENTAL FACTORS INFLUENCING DESIGN200-6202.01 INTRODUCTION200-6202.02 SOCIOECONOMIC/COMMUNITY RESOURCE DATA200-6202.02.01 Land Use200-6202.02.02 Growth Projections200-7202.02.03 Public Services200-7202.02.04 Schools200-7202.02.05 Mosques200-8202.02.06 Utilities200-8202.02.07 Security200-8202.02.08 Commercial Activities200-9202.02.09 Economics200-9202.02.10 Local Transportation/Circulation200-9202.02.11 Parking Requirements200-9202.02.12 Recreation200-10202.02.13 Historical Site Identification and Preservation200-10202.03 NATURAL/ENVIRONMENTAL RESOURCE DATA200-10202.03.01 Landscape Preservation200-10202.03.02 Topography200-11202.03.03 Water200-11202.03.04 Wildlife200-11202.03.05 Air Quality200-11202.03.06 Noise200-11
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -2-202.03.07 Visual/Aesthetic200-11202.03.08 Hazardous Materials200-11202.04 ENVIRONMENTAL CHECKLIST200-12203 TECHNICAL INVESTIGATIONS200-12203.01 INTRODUCTION200-12203.02 GEOTECHNICAL ENGINEERING200-12203.03 TRAFFIC COUNTS200-12203.03.01 Introduction200-12203.03.02 Traffic Projections200-13203.03.03 Procedures for Traffic Volumes200-14203.04 SURVEY CONTROL/FIELD SURVEYS200-14203.04.01 Introduction200-14203.04.02 Horizontal Control200-14203.04.03 Vertical Control200-14203.04.04 Coordinate System200-14203.04.05 Field Surveys200-14203.5 DRAINAGE SURVEYS200-15 SECTION 300: DESIGN CONCEPT REPORT301 CONTENTS300-1301.01 FORMAT300-1302 EXECUTIVE SUMMARY300-3303 INTRODUCTION300-3304 TRAFFIC ANALYSIS300-3305 DESCRIPTION OF ALTERNATIVES300-3306 DESIGN DATA300-4307 TYPICAL SECTIONS300-4308 GEOMETRICS300-4309 INTERCHANGE/ INTERSECTION CONFIGURATION300-5310 PARKING STUDY300-5311 HYDROLOGY AND HYDRAULICS300-5311.01 PURPOSE300-6311.02 PLANNING & PREPARATION OF THE DRAINAGE DESIGN CONCEPTS300-6311.02.01 Problem Categories300-7311.02.02 Flood Plain Encroachment and Risk Evaluation300-9311.02.03 Data Collection300-10311.03 STORM WATER HYDROLOGY300-14311.04 OPEN CHANNEL HYDRAULICS300-15311.05 BRIDGE HYDRAULICS300-16311.05.01 Bridge Location and Hydraulics Report300-16311.05.02 Bridge Hydraulics Recommendations Sheet (BHRS)300-19311.06 STORMWATER MANAGEMENT USING RETENTION/DETENTION DESIGN300-20312 SUBSURFACE INVESTIGATIONS300-21313 BRIDGE TYPE SELECTION300-21313.01 BRIDGES OVER WATERWAYS300-22313.02 WIDENINGS/REHABILITATION300-22313.03 BRIDGE SELECTION REPORT300-22314 UTILITY IMPACT ANALYSIS300-23315 SOCIOECONOMIC ANALYSIS300-23316 AGRICULTURE IMPACT300-23317 PUBLIC FEEDBACK300-24318 SIGNING AND PAVEMENT MARKINGS300-24319 LIGHTING CONCEPTS300-24320 CONSTRUCTION STAGING300-24321 COST ESTIMATE300-25322 CONCLUSIONS/RECOMMENDATIONS300-25
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -3-323 APPENDIX300-25324 DRAWINGS300-25PART 2:ROADWAY DESIGNSECTION 100: GENERAL DESIGN CRITERIA101 DESIGN SPEED100-1102 DESIGN VEHICLES100-3103 DESIGN TRAFFIC100-3103.01 DESIGN PERIOD100-3103.02 RELATION TO DESIGN100-3104 ROADWAY CAPACITY100-3104.01 DESIGN CAPACITIES100-3104.01.01 Multi-lane Rural Roadway100-4104.01.02 Two Lane Roadways100-4104.01.03 Expressways100-5104.01.04 Expressway Ramps and Weaving Sections100-5104.01.05 Intersection Capacity100-5105 CONTROL OF ACCESS100-5105.01 GENERAL100-5105.02 ACCESS CONTROL DESIGN CRITERIA100-5105.02.01 Primary Roadways100-5105.02.02 Secondary Roadways, ADT > 2500100-6105.02.03 Secondary Roadways, ADT < 2500100-6105.03 USE OF FRONTAGE ROADS100-7105.04 PROTECTION OF ACCESS RIGHTS100-7106 DESIGN STANDARD EXCEPTIONS100-7107 BICYCLE FACILITIES100-9107.01 GENERAL100-9107.02 SPECIAL BICYCLE FACILITIES100-9107.03 BICYCLE CHARACTERISTICS100-9107.04 BICYCLES AT INTERSECTIONS100-9SECTION 200: GEOMETRIC DESIGN STANDARDS201 SIGHT DISTANCE200-1201.01 GENERAL200-1201.02 PASSING SIGHT DISTANCE200-1201.03 STOPPING SIGHT DISTANCE200-1201.04 STOPPING SIGHT DISTANCE AT GRADE CRESTS200-1201.05 STOPPING SIGHT DISTANCE AT GRADE SAGS200-3201.06 STOPPING SIGHT DISTANCE ON HORIZONTAL CURVES200-3201.07 DECISION SIGHT DISTANCE200-3202 SUPERELEVATION200-3202.01 GENERAL200-3202.02 SUPERELEVATION STANDARDS200-4202.03 CITY ROAD CONDITIONS200-4202.04 AXIS OF ROTATION200-6202.05 SUPERELEVATION TRANSITION200-6202.06 SUPERELEVATION OF COMPOUND CURVES200-6203 HORIZONTAL ALIGNMENT200-9203.01 GENERAL200-9203.02 STANDARDS FOR HORIZONTAL CURVATURE200-9204 VERTICAL ALIGNMENT200-10204.01 GENERAL200-10204.02 VERTICAL ALIGNMENT POSITION WITH RESPECT TO CROSS SECTION200-10204.03 STANDARDS FOR GRADES200-10
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -4-204.04 VERTICAL CURVES200-11204.05 LONG SUSTAINED GRADES200-11204.06 STRUCTURE GRADE LINE200-11204.07 SEPARATE PROFILE GRADE LINES200-16205 COORDINATION OF HORIZONTAL AND VERTICAL ALIGNMENTS200-16206 PAVEMENT TRANSITIONS200-16206.01 GENERAL200-16206.02 TRANSITIONS FOR MULTILANE ROADWAYS200-16207 BRIDGES AND GRADE SEPARATION STRUCTURES200-18207.01 CLEAR WIDTH200-18207.02 CROSS SLOPE200-18207.03 SIDEWALKS200-18208 PEDESTRIAN FACILITIES200-18208.01 SIDEWALKS200-18208.02 PEDESTRIAN GRADE SEPARATIONS200-18208.03 PEDESTRIAN UNDERPASSES200-18209 CURBS200-18209.01 GENERAL200-18209.02 TYPES AND USES200-19209.03 CURB PARAMETERS200-19210 BUS STOPS AND TAXI STOPS200-19210.01 BUS STOPS200-19210.02 TAXI STOPS200-19211 PARKING200-20211.01 GENERAL200-20211.02 PARKING AREAS200-20211.03 ON ROAD PARKING SPACES200-20211.04 PARKING LOTS200-21211.05 PARKING DEMAND/SUPPLY ANALYSIS200-21SECTION 300: GEOMETRIC CROSSECTIONS301 TRAVELLED WAY STANDARDS300-1301.01 TRAVELLED WAY WIDTH300-1301.02 TRAVELLED WAY CROSS SLOPES300-1302 SHOULDER STANDARDS300-1302.01 SHOULDER WIDTH STANDARDS300-1302.02 SHOULDER CROSS SLOPES300-1303 SIDE SLOPE STANDARDS300-1303.01 SIDE SLOPE VALUES300-2303.02 SLOPE CLEARANCE FROM RIGHT OF WAY300-2304 MEDIAN STANDARDS300-2305 CROSS SECTION ELEMENTS300-2305.01 RURAL FREEWAY/EXPRESSWAY CROSS SECTION300-2305.02 URBAN FREEWAY/EXPRESSWAY CROSS SECTION300-2305.03 ARTERIAL (MAIN ROAD) CROSS SECTION300-4305.04 SECTOR ROAD CROSS SECTION300-5305.05 FRONTAGE ROAD CROSS SECTION300-5306 HORIZONTAL AND VERTICAL CLEARANCES300-5306.01 HORIZONTAL CLEARANCES300-5306.02 VERTICAL CLEARANCES300-6306.03 TUNNEL CLEARANCES300-6307 CLEAR ZONE CONCEPT300-6307.01 APPLICATION OF CLEAR ZONE300-8307.01.01 Roadside Terrain: Foreslope300-8307.01.02 Roadside Terrain: Backslope300-9307.01.03 Roadside Terrain: Cross-slope300-9
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -5-307.01.04 Roadside Terrain: Ditch300-9308 BARRIERS300-11308.01 BARRIER NEED300-11308.02 ROADSIDE BARRIER TYPES AND FEATURES300-11308.03 ROADSIDE BARRIER PLACEMENT300-12308.03.01 Lateral Placement300-12308.03.02 Barrier to Hazard Clearances300-12308.03.03 Effects of Roadside Terrain300-13308.03.04 Barrier Length Design300-13308.04 MEDIAN BARRIERS300-15308.04.01 Median Barrier Warrants300-15308.04.02 Median Barrier Types and Features300-15308.05 MEDIAN BARRIER PLACEMENT300-15308.05.01 Median Geometry300-15308.05.02 Treatment of Fixed Object Hazards300-16308.06 END TREATMENTS AND CRASH CUSHIONS300-16308.06.01 End Treatments300-16308.06.02 Crash Cushion-Selection Guidelines300-18308.06.03 Placement Recommendations300-18SECTION 400: AT-GRADE INTERSECTIONS401 GENERAL400-1402 DESIGN CONSIDERATIONS400-1403 AT GRADE INTERSECTION TYPES400-1404 CHANNELIZATION400-2404.01 PREFERENCE TO MAJOR MOVEMENTS400-2404.02 AREAS OF CONFLICT400-2404.03 INTERSECTION ANGLES400-2404.04 POINTS OF CONFLICT400-2404.05 SPEED-CHANGE LANES400-3404.06 TURNING MOVEMENTS400-3404.07 REFUGE AREAS400-3404.08 PROHIBITED TURNS400-3404.09 EFFECTIVE SIGNAL CONTROL400-3404.10 INSTALLATION OF TRAFFIC CONTROL DEVICES400-3404.11 GUIDELINES400-3405 DESIGN VEHICLES400-4405.01 OFF TRACKING400-4405.02 DESIGN VEHICLES400-4405.03 TURNING TEMPLATES400-4406 INTERSECTION DESIGN STANDARDS400-4406.01 SIGHT DISTANCE400-4406.02 EFFECT OF SKEW400-10406.03 EFFECT OF VERTICAL PROFILES400-13406.04 LEFT-TURN CHANNELIZATION400-13406.05 RIGHT-TURN CHANNELIZATION400-14406.06 TRAFFIC ISLANDS400-14407 ROUNDABOUT DESIGN400-15SECTION 500: INTERCHANGES501 GENERAL500-1502 INTERCHANGE WARRANTS500-1503 DESIGN CONSIDERATIONS500-1504 INTERCHANGE TYPES500-1504.01 THREE-LEG INTERCHANGE500-1504.02 FOUR-LEG INTERCHANGES500-3
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -6-505 INTERCHANGE DESIGN PROCEDURES500-8506 INTERCHANGE DESIGN STANDARDS500-8507 RAMP DESIGN STANDARDS500-9508 ENTRANCE/ EXIT RAMP DESIGN STANDARDS500-11508.01 RAMP TERMINAL DESIGN500-16SECTION 600: GEOTECHNICAL ENGINEERING601 INTRODUCTION600-1602 GENERAL600-1603 GEOTECHNICAL REPORT600-1604 STRUCTURAL PAVEMENT SECTION DESIGN600-2604.01 GENERAL600-2604.01.01 Pavement Design Methods600-2604.01.02 Comparison of Design Results600-4604.02 PAVEMENT DESIGN METHOD600-5SECTION 700: DRAINAGE701 GENERAL700-1SECTION 800: UTILITIES801 GENERAL800-1802 UTILITY PLANNING800-1803 SERVICE RESERVATIONS800-2804 UTILITY DESIGN800-3804.01 GENERAL800-3804.02 UTILITY PROTECTION800-3804.03 UTILITY RELOCATION800-4804.04 CONTINGENCY DUCTS800-4804.05 UTILITY LOCATIONS800-4804.06 NON-DISRUPTIVE ROAD CROSSINGS800-4SECTION 900: TRAFFIC ENGINEERING901 TRAFFIC OPERATIONAL ANALYSIS900-1901.01 GENERAL900-1901.02 OPERATIONAL ANALYSIS900-1902 SIGNALIZATION900-1902.01 TRAFFIC SIGNAL DESIGN900-1902.02 SIGNALS, POLES, AND CONTROLLERS900-2902.03 DUCTS AND PULLBOXES900-3902.04 PYLONS900-3903 TRAFFIC SURVEILLANCE900-3904 SIGNING900-3904.01 SIGN STRUCTURE INSTALLATIONS900-4904.01.01 Ground Mounted900-4904.01.02 Overhead Mounted900-4904.02 SIGN SHEETING900-5904.03 SIGN TYPES900-5904.03.01 Regulatory And Warning Signs900-5904.03.02 Guide Signs900-5904.04 FINAL SIGNING PLAN REQUIREMENTS900-5904.05 ARABIC LETTERING FOR GUIDE SIGNS900-10904.05.01 General900-10904.05.02 The Arabic Alphabet900-10904.05.03 Use of the Standard Arabic Script900-10904.06 GUIDE SIGN DIMENSIONS900-10
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -7-904.06.01 Single Message Guide Signs (Example 900-02)900-10904.06.02 Multiple Message Guide Signs (Example 900-03)900-12904.07 STANDARD ARABIC SCRIPT FOR HIGHWAY SIGNS1 OF 14900-15904.08 SIGN LIGHTING900-29904.09 SIGN LUMINARES900-29905 PAVEMENT MARKINGS900-29905.01 GENERAL900-29905.02 TYPES OF PAVEMENT MARKINGS900-29905.02.01 Lane Markings900-29905.02.02 Stop Line Markings900-30905.02.03 Pedestrian Crossing Markings900-30905.02.04 Channelization Markings900-30905.02.05 Pavement Edge Markings900-30905.02.06 Parking Space Markings900-30905.02.07 Pavement Symbols900-30906 MAINTENANCE OF TRAFFIC900-30906.01 CONSTRUCTION STAGING900-30906.02 SAFETY MEASURES900-31906.03 TEMPORARY TRAFFIC SIGNALS900-31906.04 MAINTENANCE OF TRAFFIC PLANS900-31SECTION 1000: LIGHTING1001 ROADWAY LIGHTING1000-11001.01 GENERAL1000-11001.02 LIGHTING DESIGN CONSIDERATIONS1000-11001.03 ILLUMINATION REQUIREMENTS1000-21002 PARKING AREA LIGHTING1000-31002.01 GENERAL1000-31002.02 ILLUMINATION REQUIREMENTS1000-31002.03 LANTERN MOUNTING HEIGHT1000-41002.04 LANTERN SELECTION1000-41003 SIDEWALK LIGHTING1000-41003.01 GENERAL1000-41003.02 ILLUMINATION REQUIREMENTS1000-41003.03 LANTERN MOUNTING HEIGHT1000-41003.04 LANTERN SELECTION1000-41004 LIGHTING CONTROLS1000-41004.01 GENERAL1000-41004.02 LIGHTING CONTROLLER REQUIREMENTS1000-41004.03 DESIGN STANDARDS AND PROCEDURES1000-41005 POWER DISTRIBUTION1000-41006 DESIGN AND SUPERVISION RESPONSIBILITIES1000-5SECTION 1100: ROADSIDE DEVELOPMENT1101 LANDSCAPING1100-11102 IRRIGATION1100-11102.01 IRRIGATION DUCTS1100-11103 FENCING1100-21104 SLOPE PAVING1100-21105 SWEET SAND COVERING1100-21106 STREET FURNITURE1100-21106.01 GENERAL1100-21106.02 DESIGN1100-21106.03 BENCHES1100-21106.03.01 Type A bench1100-21106.03.02 Type B bench1100-2
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -8-1106.03.03 Type C bench1100-31106.04 BUS SHELTERS1100-31106.05 TELEPHONE BOOTHS1100-31107 NOISE ABATEMENT1100-3PART 3:STRUCTURE DESIGNSECTION 100: DESIGN CRITERIA101 GENERAL100-1101.01 PURPOSE100-1101.02 DEFINITIONS100-1101.03 BRIDGE TYPES100-1102 DESIGN FEATURES100-2102.01 GENERAL100-2102.02 DESIGN METHODS100-2102.03 VERTICAL CLEARANCE AT STRUCTURES100-2102.03.01 Highway Traffic Structures100-2102.03.02 Pedestrian Overpasses100-2102.03.03 Railroad Overpasses100-2102.03.04 Tunnels100-3102.03.05 Sign Structures100-3102.03.06 Width100-3102.04 RAILINGS100-3102.05 CONCRETE BARRIER TRANSITIONS100-3102.06 APPROACH SLABS100-3102.07 ANCHOR SLABS100-3102.08 DECK DRAINAGE100-3102.09 WING WALLS100-4102.10 LIGHTING100-4102.11 BRIDGE DECK ELEVATIONS100-4102.12 CONCRETE CRACK CONTROL100-4102.13 CORROSION PROTECTION100-4103 ARCHITECTURAL CONSIDERATIONS100-4103.01 PROCEDURE100-4103.02 GENERAL CRITERIA100-5SECTION 200: DESIGN LOADS201 LOAD TYPES200-1201.01 GENERAL200-1201.02 DEAD LOADS200-1201.03 FUTURE WEARING SURFACE200-1201.04 WEARING SURFACE200-1201.05 HIGHWAY LOADS200-1201.06 STRUCTURE LOADINGS200-1201.07 FRICTION FORCES200-1201.08 THERMAL FORCES200-1201.09 STREAM FORCES200-1201.10 LATERAL EARTH PRESSURE200-3201.11 DIFFERENTIAL SETTLEMENT200-3201.12 EARTHQUAKES200-3202 DISTRIBUTION OF LOADS200-4202.01 SUPERIMPOSED DEADLOAD DISTRIBUTION200-4202.02 CONCRETE BOX GIRDERS200-4202.03 PRESTRESSED VOIDED SLABS200-4202.04 PRESTRESSED BOX BEAMS200-4202.05 LATERAL TENSIONING OF MULTI-BEAM UNITS200-5
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -9-202.06 LIVE LOAD DISTRIBUTION200-5203 LOAD FACTORS200-5SECTION 300: REINFORCED CONCRETE301 GENERAL300-1301.01 CONCRETE300-1301.02 DIAPHRAGMS300-1301.03 DESIGN METHODS300-1301.04 REINFORCEMENT300-1302 SLAB DESIGN300-1302.01 SPAN LENGTHS300-2302.02 SLAB THICKNESS300-2302.03 PROTECTION AGAINST CORROSION300-2302.04 DISTRIBUTION METHOD300-2302.05 RAILING LOADS300-2SECTION 400: PRESTRESSED CONCRETE401 DESIGN CRITERIA400-1401.01 GENERAL400-1401.02 ALLOWABLE STRESSES—CONCRETE400-1401.03 SHEAR400-1402 POST TENSIONED BOX GIRDER BRIDGES400-2402.01 GENERAL400-2402.02 CONCRETE400-2402.03 BEARING PADS400-2402.04 CREEP AND SHRINKAGE400-2402.05 FLANGE AND WEB THICKNESS - BOX GIRDERS400-2402.06 DIAPHRAGMS400-2402.07 DEFLECTIONS400-2402.08 ALLOWABLE STRESSES - PRESTRESSING STEEL400-2402.09 ALLOWABLE STRESSES-CONCRETE400-2402.10 LOSS OF PRESTRESS400-3402.11 FLEXURAL STRENGTH400-3402.12 SHEAR400-3402.13 FLANGE REINFORCEMENT400-3402.14 METHOD OF ANALYSIS400-3403 PRECAST PRESTRESSED CONCRETE400-4403.01 CONCRETE400-4403.02 DEFLECTIONS400-4403.03 ALLOWABLE STRESSES-PRESTRESSING STEEL400-4403.04 ALLOWABLE STRESSES-CONCRETE400-5403.05 LOSS OF PRESTRESS400-5403.06 SHEAR400-5403.07 METHOD OF ANALYSIS400-5404 PRESTRESSED I-GIRDERS400-5404.01 GENERAL400-5404.02 CONCRETE400-5404.03 EFFECTIVE FLANGE WIDTH400-6404.04 SHEAR400-6404.05 INTERMEDIATE DIAPHRAGMS400-6404.06 BEARING PADS400-6404.07 CREEP FACTOR400-6404.08 FRAMES AND CONTINUOUS CONSTRUCTION400-6404.09 DIFFERENTIAL SHRINKAGE400-7404.10 METHOD OF ANALYSIS400-7405 PRESTRESSSED VOIDED SLABS400-7
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -10-405.01 END BLOCKS400-7405.02 DIAPHRAGMS400-7405.03 LATERAL TIES400-7405.04 SHEAR KEYS400-7405.05 BARRIERS400-7406 PRESTRESSED BOX BEAMS400-7406.01 END BLOCKS400-7406.02 DIAPHRAGM400-7406.03 LATERAL TIES400-7406.04 SHEAR KEYS400-7SECTION 500: STRUCTURAL STEEL501 DESIGN CRITERIA500-1501.01 GENERAL500-1501.02 DESIGN METHODS500-1501.03 MATERIALS500-1501.04 ALLOWABLE FATIGUE STRESS500-1501.05 LOAD CYCLES500-1501.06 CHARPY V-NOTCH IMPACT REQUIREMENTS500-1SECTION 600: EXPANSION AND CONTRACTION601 MOVEMENT CRITERIA600-1601.01 MOVEMENT RATING600-1602 DECK JOINTS600-1602.01 GENERAL600-1602.02 COMPRESSION SEALS600-2602.03 STRIP SEALS600-2602.04 MODULAR JOINTS600-2603 BEARINGS600-2603.01 GENERAL600-2603.02 NEOPRENE STRIPS600-3603.03 ELASTOMERIC BEARING PADS600-3603.04 STEEL BEARINGS600-4603.05 SLIDING ELASTOMERIC BEARINGS600-4603.06 HIGH-LOAD MULTI-ROTATIONAL BEARINGS600-4603.06.01 Description600-4603.06.02 Rotational Requirements600-5603.06.03 Use600-5603.06.04 Design Criteria600-5603.07 BEARING SCHEDULE600-7604 RESTRAINING DEVICES600-7604.01 GENERAL600-7604.02 VERTICAL FIXED RESTRAINERS600-7604.03 VERTICAL EXPANSION RESTRAINERS600-8604.04 EXTERNAL SHEAR KEYS600-8604.05 INTERNAL SHEAR KEYS600-8604.06 KEYED HINGE600-8SECTION 700: GEOTECHNICAL701 FOUNDATIONS700-1701.01 GENERAL700-1701.02 SPREAD FOOTINGS700-1701.03 PILE FOUNDATIONS700-1701.04 DRIVEN PILES700-2701.05 BORED PILES700-2
ROADWAY DESIGN MANUAL – Roads and BridgesTTaabblleeooffCCoonntteennttssPPaaggeeNNoo..Page -11-SECTION 800: RETAINING WALLS801 DESIGN CRITERIA800-1801.01 GENERAL800-1801.02 POLICY800-1801.03 RESPONSIBILITIES800-1801.03.01 Roadway Design Section800-1801.03.02 Geotechnical Section800-2801.03.03 Bridge Design Section800-2801.04 PROPRIETARY RETAINING WALLS800-2SECTION 900: MISCELLANEOUS901 TRAFFIC STRUCTURAL SUPPORTS900-1901.01 GENERAL900-1901.02 WIND SPEED900-1901.03 ALLOWABLE STRESSES900-1902 UTILITIES IN STRUCTURES900-1902.01 GENERAL900-1902.02 POLICY900-2902.03 UTILITY AGENCY RESPONSIBILITY900-2902.04 BRIDGE GROUP RESPONSIBILITY900-2903 FALSEWORK POLICY FOR BRIDGE CONSTRUCTION900-3903.01 FALSEWORK REQUIREMENTS900-3903.02 FALSEWORK USE900-3903.03 FALSEWORK CLEARANCES900-3904 CONSTRUCTION JOINT GUIDELINES FOR BRIDGE CONSTRUCTION900-5904.01 GENERAL900-5904.02 LONGITUDINAL CONSTRUCTION JOINTS900-5904.03 PRECAST CONCRETE GIRDER BRIDGES900-5904.04 STEEL GIRDER BRIDGES900-6904.05 CAST-IN-PLACE BOX GIRDER BRIDGES900-6
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1100-1PART 1ROADWAY DEVELOPMENTSECTION 100GENERAL INFORMATION101PURPOSE101.01INTRODUCTIONThe Manual is intended to serve as a guide for thedesign of the roads and highways that fall underthe jurisdiction of the Road Section, Abu DhabiMunicipality. The Manual provides a range of acceptable values for critical dimensions andoutlines parameters that will help designersconform to the expectations of the Road Sectionof the Abu Dhabi Municipality. It is assumedthat the user has the educational and engineeringexperience necessary to properly implement itsprocedures, guidelines and criteria.It is perceived that this manual will promote thefollowing:1.All designs will be based on identicalcriteria.2.Plans will have a consistent,well-organized format which will notvary greatly from project to project.3.Familiarization of criteria and procedureswill be simplified.4.The technical review process will beexpedited for both the Road Section andthe Consultant.5.Cost efficiencies will be realized duringdesign by an early understanding of procedures and criteria to be employed.The manual is presented in loose-leaf form tofacilitate revisions and additions. This manualutilized established analysis techniques and designstandards from recognized technical associationsthat are listed as references in Appendix A.When the Roadway Design Manual is combinedwith the four companion documents listed below,the standardization of the planning, design andconstruction of roadway projects will becomplete. The companion documents to thismanual are:z Standard Specifications for Roads andBridge Construction - 1996z Consultant Procedures Manual - 1997z Roadway Standard Drawings - 1996z Construction Supervision Manual - 1997Where the Consultant's scope of work and thismanual conflict, the scope of work shall govern.Revisions and additions to this manual will beissued from time to time as required. This sectioncontains information regarding technicalmemorandums used to submit future revisionsand additions.Further contained in this section is an overview of the layout of the manual content, roadwayclassifications, route designations connectingU.A.E cities and emirates, and streets and placenames as assigned by Abu Dhabi Municipality.102CONTENTS ANDORGANIZATIONThe scope of the Roadway Design Manual iscomprehensive, and is divided into three parts.The three parts are further divided into sections,each with appropriate sub-sections.
The threeparts are:Part 1Roadway DevelopmentPart 2Roadway DesignPart 3Structures and Bridges102.01PART 1:ROADWAYDEVELOPMENTThe purpose of the Roadway Development part isto outline the information and data which must beanalyzed to determine a project’s scope. Thisinformation and analyses are assembled into aDesign Concept Report, which becomes the basisfor the project design.The Roadway Development part is divided intothree sections. The first section explains theformal organization of this manual and the othertwo sections, the Design Concept Development
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1100-2and the Design Concept Reports, define theconceptual design of the project.The Design Concept Section includes subsectionsin Transportation Planning, Socio-economicData, and Technical Investigations. ConceptualDesign must be based upon site specificcommunity considerations that reflect military,utility, environmental features, physical propertiesof the site, and circulation that define the projectdesign. To support the land’s intended use,procurement of the information from departmentswithin the Municipality and outside of Municipality’s organization is required.All the Project-specific data collected forms thebasis for the Design Concept Report, a summaryof the technical analyses and schematic designthat are to be used for plan preparation andconstruction.102.02PART 2:ROADWAY DESIGNThe purpose of the Roadway Design part is toidentify the design standards that all roadwayprojects are required to meet. The project designis based on these standards. When used inconjunction with the Standard Specifications forRoad and Bridge Construction, and Abu DhabiRoadway Standard Drawings, the resultingproject plans and specifications for all projectsare completed to the same requirements andformat.Specifically, the Roadway Design Part providesdetails in geometric design standards for eachcomponent of the roadway project. Theinformation is divided into eleven sections thatinclude General Design Criteria, GeometricStandards, Geometric Cross Sections, At GradeIntersections, Interchanges, GeotechnicalEngineering, Drainage, Utilities, TrafficEngineering, Lighting, and RoadsideDevelopment.102.03PART 3:STRUCTURES ANDBRIDGESThe purpose of the Structures and Bridges part isto identify the design details with which allstructures are required to comply. As with theRoadway Design part, this document is intendedto be used in conjunction with the StandardSpecifications and the Abu Dhabi StandardDrawings for the standardization of details forstructures and bridges.Uniform design and construction of structures andbridges promotes efficiency of design,construction, and maintenance. This part focuseson features incorporating sound design and cost-effective design practices to meet this goal.This part consists of nine sections that cover thegeneral aspects of structures and bridge design.Subjects covered include, General DesignCriteria, Design Loads, Reinforced Concrete,Prestressed Concrete, Structural Steel,Expansions and Contractions, Geotech andRetaining Walls. The last section addressesmiscellaneous items such as Traffic Supports,Utilities and the Falsework Policy andRequirements.103TECHNICAL MEMORANDUMS103.01GENERALThis manual will be supplemented from time totime with technical memorandums (TM)addressed to the Consultants for the purpose of transmitting and formalizing appropriate revisionsor additions, to the manual. This manual canonly be revised by the issuance of a TMauthorized and signed by the Chief of RoadSection, Abu Dhabi Municipality or hisdesignated representative. Technicalmemorandums will be developed and issued astwo distinct types, general and specific, and arefurther defined below.103.02TECHNICAL MEMORANDUMS- GENERAL
Technical Memorandums - General, deal withissues or information that must be distributed on asystem wide basis to all consultants. They arealso used to provide advance directives withrespect to imminent revision or additions to theRoadway Design Manual. Examples arerevisions or refinements to policies, guidelines orcriteria.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1100-3103.03TECHNICAL MEMORANDUMS- SPECIFICTechnical Memorandums - Specific, deal withissues or information that is of specific interest toa particular section (design contract), and as suchhave no influence or effect on other designsections.Examples of such memorandums are:1.Deviations from the Design ProceduresManual on a project specific basis.2.Drainage Design Guidelines.3.Lighting Design Guidelines.4.Report Transmittals, etc.104ROADWAY CLASSIFICATIONS104.01ROADWAY SYSTEMRoadways within the jurisdiction of Abu DhabiMunicipality are classified into one of threefunctional categories, consistent with theTransportation Master plan:z Primary Roads Freeways Expresswaysz Secondary Roads Arterials Collectorsz Local RoadsThe design classes discussed in this section areapplicable to all highway networks in both ruraland urban areas under the jurisdiction of the RoadSection, Abu Dhabi Municipality.Table 100.01 summarizes the majorcharacteristics of the first tier classifications,i.e.,primary, secondary and local roads.Table 100.02 is a matrix that differentiates theurban and rural roadway types by their first tierclassifications.104.02DESIGNRoadway design standards are dependent on theclassification of the roadway. The Road Sectionwill determine the classification. The DesignConcept Report summarizes the design criteria tobe utilized in the design.The roadway classification system is based on ahierarchy of roads. Local roads provide access toadjacent land. Collectors provide a combinationof land access and movement of through traffic.Arterials and expressways provide for movementof through traffic. Arterials and Expresswayshave at-grade or grade-separated intersections.Freeways shall have only grade-separatedcrossings and interchanges.104.03CRITERIA FOR DESIGN CLASSDESIGNATIONTable 100.03 defines the characteristics of thesecond-tier classifications,
i.e., freeways,expressways, arterials, and collectors as theyrelate to design requirements.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1100-4Table 100.01Summary of Functional Characteristics for Roadway Classifications* Primary RoadsSecondary RoadsLocal RoadsFunctionRegionaltransportationRegional transportationand/or service to majorland developmentsLocal circulationService PointsConnects multipleregions. Servesinternationalconnections and majormilitary installations.Connects two regions.Serves internationalconnections, militaryinstallations andseaports not served byPrimary Roads. Mayconnect two PrimaryRoads.Residential,industrial, andrecreational areasnot served by higherclass.Population DensityConnections to urbanareas of 100,000 ormore.Connections to urbanareas of 50,000 ormore.NoneAccessAccess is controlled.May be controlled.Minimal control.Minimum Level of ServiceC/DCDPercent of Total Kilometers353530Design Speed120 kph (urban)140 kph (rural)60 kph (urban)60-100 kph (rural)50 kph (urban)60-90 kph (rural)Weather Related RoadClosures - AllowableFrequencyOnce per 100 years.Once per 50 years.Once per 25 years.Minimum Percent of Truck Traffic (Other Than Pickups)252030* See Part 2.0 for further details.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1100-5105ROUTE DESIGNATIONS105.01INTRODUCTIONThe purpose of route designations is to providethe highway user with a consistent expectation of the:z relative direction (north, south, eastwest)z design standards (design speeds,shoulders, etc. resulting from the highway classification)z origin/destination of the road.Route designation and numbering facilitate rapidand accurate identification of specific locations inthe event of emergencies, accident reporting andanalysis and in the inventory of roadwayappurtenances,i.e., signs, drainage structures,guardrails, etc. Route assignments are made bythe Municipality and based on the functionalclassification of each roadway.105.02ROUTE NUMBERSFigure 100.01 shows the designated routenumbers between emirates and cities within theU.A.E.Figure 100.02 shows routes designated betweenexisting primary roads and secondary or localroads in the Abu Dhabi Emirate.105.03ADDITIONS, DELETIONS, ANDREVISIONSFrom time to time, it may become necessary toassign new route numbers, delete route numbersfor obsolete roads or revise route numbers toreflect changes to road classifications. Users of this manual shall advise the Municipality if theyperceive the need for changes to the routenumbering system. Note that all changes of thisnature are subject to the approval of Abu DhabiMunicipality.Table 100.02Roadway Types by Functional Classification RoadwayRoadway Type for DesignClassificationUrbanRural PrimaryFreewayExpresswayFreewayExpresswaySecondaryArterial(Main Roads)Frontage RoadsCollector• Major• MinorLocalSector Road•
Primary• LocalLocal Access
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1100-6 Table 100.03Characteristics of Urban/Rural Design Classes Freeways/ Expressways ArterialsCollectorsLocalsTraffic Service:Urban andRuralOptimum mobilityTraffic movementprimaryconsiderationTraffic movementand land access of equal importance.Traffic movementsecondaryconsiderationLand Service:Urban andRuralFull control of access−no direct land accessLand accesssecondary inconsiderationTraffic movementand land access of equal importance.Land accessprimaryconsiderationTraffic Flow Characteristics:Urban andRuralFree flowUninterruptedexcept atintersectionsInterrupted flowInterrupted flowPrivate and Commercial Access:Urban andRuralNot permittedNone or limitedPermittedPermittedConnection Type for Public Roads:UrbanGrade separations &interchangesAt-gradeintersections,interchanges,orslip-rampsAt-gradeintersectionsAt-gradeintersectionsRuralGrade separations &interchangesAt-gradeintersections orinterchangesAt-gradeintersectionsAt-gradeintersectionsConnects to:UrbanArterialsExpresswaysFreewaysArterialsExpresswaysLocals ArterialsLocalsRuralExpresswaysCollectorsFreewaysLocals CollectorsExpresswaysLocals CollectorsLocals CollectorsVehicle Type:UrbanAll types up to 20percent heavy trucksAll types up to 20percent heavytrucksAll typesPassenger &service vehiclesRuralAll types; heavy trucksaverage 20%-40%All types up to40% trucksAll types, up to30% heavy trucksin the 3 mg to 5mg classPredominantlypassenger cars &light to mediumtrucks: occasionalheavy trucksADT (20):UrbanLevel of Service is C/D5,000-30,0001,000-12,000100-1,000RuralLevel of Service is C/D2,000-15,000200-4,0000 to 300Average Running Speed for Off-Peak Conditions:Urban80-110 kph50-80 kph30-50 kph30-40 kphRural80-120 kph60-110 kph50-90 kph45-80 kph
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1100-7Figure 100.01Route Designations Between U.A.E. Cities and Emirates
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1100-8Figure 100.02Connections Between Primary and Secondary or Local Roads
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1200-1SECTION 200DESIGN CONCEPTDEVELOPMENT201TRANSPORTATIONPLANNING201.01INTRODUCTIONData collection comprises this phase of the pre-design process. Existing data is collected fromthe Abu Dhabi Municipality, other governmentdepartments, landowners, and field surveys. Thisdata becomes the foundation for project road andbridge design. The Consultant is responsible forall data collection.201.02ROAD SECTIONThe Road Section is the lead department fromwhich all road and bridge projects are initiatedand approved.The Consultant shall work with assigned staff todevelop the project scope per the ConsultantProcedures Manual and identify applicable designcriteria from the Roadway Design Manual. TheConsultant is expected to develop the project byproper application of Abu Dhabi Municipalitypolicies and standards.201.03TOWN PLANNINGThe Town Planning Department is comprised of two sections:Planning Section -The Planning Section isresponsible for the development and maintenanceof the Master Plan and planning layouts. TheMaster Plan is the base document from which theproject’s roadway classifications are assigned.Roadway design standards are identified for eachroadway classification (see Tables 100.01,100.02 and 100.03, in Part 1, Section 100,General Information).The planning layouts are used to identify theexisting and proposed land use and developmentintensity.Utilities Section -The Town Planning UtilitiesSection is responsible for the development andapproval of all service reservations.201.04MAPPING201.04.01GeneralCurrent, accurate base mapping is an essentialtool in transportation planning. The specificmapping requirements depend on the length andcomplexity of the project and its location, eitherurban or rural. Aerial mapping is normally themost useful and cost-effective medium for largerprojects. Ground topographical surveys are usedfor smaller projects, especially in urban areas andto supplement aerial mapping at specific locationswhere more detail and accuracy is needed.Three types of aerial maps are used in theplanning and design phases of roadway andbridge projects:Uncontrolled Aerial Photography -These mapsare produced directly from the aerial photographsthat normally cover large areas at a reduced scale.The maps are generally used in route locationstudies to define transportation corridors andalternative alignments. The contact prints fromthe aerial photography are assembled to form aphotomosaic of the area under study to reducedistortion.Controlled Aerial Photography -Prior to theflight, horizontal and vertical ground controlpoints are set and marked in the field. Thesepoints are used to control photomosaic productsthat are significantly more
accurate and can beprepared at a specific scale. These maps can beused at larger scales for preliminary engineeringactivities including Design Concept Reports.Topographic (Aerial) Mapping -These mapsrepresent the state-of-the-art in highway designand consist of topographic maps compiled fromcontrolled aerial photography in a digitizedformat that can be input directly to CADD. Thismapping can be used for both design conceptdevelopment and final design and is limited to thebroad roadway corridor.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1200-2The Consultant is responsible for providing basemapping for design concept development.Specific requirements will be identified in theConsultant’s scope of work. Existing aerial andtopographic maps may be available and suitablefor use in consultation with the Department. TheAbu Dhabi Municipality and Town PlanningDepartment maintain a limited library of existingmapping which the Consultant shall review forbackground information.Mapping scales and contour intervals generallysuitable for the intended purpose are shown inTable 200.01.201.04.02Topographic MappingTopographic maps for a specific project shall beprepared in accordance with the following:Survey Control/Field Surveys- Therequirements for surveys are included in Section203.04, Survey Control/Field Survey.CADD Standards- Mapping features andsymbology will be prepared in accordance withthe latest CADD Standards, supplemented by thestandard symbols shown in Figure 200.01, 200.02and 200.03.Primary Control Points -All primary controlpoints for mapping which were established duringthe initial field survey will be shown on the mapsin their proper locations and with the appropriatesymbol, identification number and elevation. Atabulation of the primary control points shall alsobe shown in the original survey notebook. Thetabulation will show the identification number,coordinates and elevation of the point.Supplemental Control Points -All supplementalcontrol points established for controlling aerialphotography will be shown on the maps. Theseinclude wing points, analytically bridged points,and aerial photo centers. See Figure 200.01.Planimetric Features -Natural and manmadefeatures, spot elevations, topographic features andrelevant political subdivision lines shall be plottedon the maps as shown in Figure 200.02 andFigure 200.03.Coordinate Grid -Coordinate grid ticks shall beshown on the maps at intervals to suit drawing.North Arrow -A north arrow shall be placed oneach map sheet. The north arrow shall beoriented so that north points to the top or to theright of the map sheet. Match lines shall also belabeled so that each sheet may be joinedaccurately to adjacent sheets.Map Index -A sheet index diagram shall beprepared for each mapping project. This diagramshall show the position and relationship of eachsheet to adjacent sheets. A title block is alsorequired and shall be placed on each sheet.Table 200.01Map Scales and Contour Intervals forHighway Development
PurposeScalesInterval (m)Route Location Studies:Mountainous1:5000 Max.5Rolling to Flat1:50002Preliminary Design (DCR):Rural 1:12502Urban1:12502Rural Design:1:12500.5Urban Design:1:5000.5Detailed Site Design:1:1000.51:2500.5201.05PROJECT LIMITSThe Abu Dhabi Municipality will determine thelimits of the project. Typically, the limits includethe roadway/bridge, medians, sidewalk,parkways, and roadside improvements thatenhance the appearance, maintainability andsafety characteristics of the project. The projectlimits may also be determined by phasedimplementation considerations.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1200-3Figure 200.01Standard Mapping Symbols - Boundaries and Monuments
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1200-4Figure 200.02Standard Mapping Symbols - Natural Planimetric Features
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1200-5Figure 200.03Standard Mapping Symbols - Manmade Planimetric Symbols
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1200-6201.06PROJECT IDENTIFICATIONAND NUMBERINGThe Abu Dhabi Municipality Road Section willassign the Title and Number for each individualroadway and bridge project. The Consultant willinclude this information on all drawings, reports,correspondence, calculations and other designdocumentation associated with the subject project.201.07INTERDEPARTMENTALCOORDINATIONThroughout the development of the project,coordination with Municipality Sections as wellas other government departments is essential.The Consultant is expected to identify therequirements of the involved governmentdepartments, and insure that the project designaddresses these requirements. Table 200.02 liststhe agency or authority responsible fortransportation related functions.Table 200.02Municipal Agencies FunctionAgency/AuthorityRoad/BridgeConstructionADM-Road SectionPlanningADM-Town Planning Dept.UtilitiesADM-Town Planning Dept.ParkingADM-Road SectionRight-of-WayADM-Town Planning Dept.PlantationADM-Agriculture Section202ENVIRONMENTAL FACTORSINFLUENCING DESIGN202.01INTRODUCTIONThere are a number of important environmentalfactors that influence the design of all roadwayand bridge projects. These factors are bothnatural and man-made and have been divided intotwo major categories; Socioeconomic/ Community Resource Data and Natural/ Environmental Resource Data. The identificationof these resources enables the project to bedeveloped to avoid and/or minimize impact tothese resources to the greatest extent practicable.This will contribute significantly to publicacceptance and the ultimate success of a project.The following sections describe the variousenvironmental factors that comprise each of thetwo categories. It is the Consultant’sresponsibility to assess each factor and develop afunctional and compatible design.202.02SOCIOECONOMIC/COMMUNITYRESOURCE DATAThe Consultant shall consider each of thefollowing factors as part of the development of project design. The goal is to develop afunctional design that accommodates or maintainsthe integrity of each socioeconomic andcommunity resource with minimal disruption. Toassist with the planning involved with thedevelopment of the design, the Consultant shouldmap all resources that are capable of being placedonto a map.202.02.01Land UseThe project plans must accommodate existing andfuture land use to the extent possible. TheConsultant is required to provide adequateparking and access to adjacent land uses,commensurate with the type of land use and theroadway classification (see Tables 100.01,100.02 and 100.03, Part 1, Section 100, GeneralInformation). The roadway volumes used todetermine the “level of service” (existing and 20-year projection) must include the trip generationassociated with the adjacent land uses.In the urban areas, the Town Planning MasterPlan is the primary document used to identify thetypes and locations of designated land uses. Inrural areas, where the land usage is less defined,the Consultant must conduct a field survey of theexisting land uses adjacent to the project.
Theaforementioned information, combined with thefield survey data, will then be used to identifypotential improvements to be designed as part of the roadway project.In rural areas, formal information regarding landuse may not be available. In these cases, thecurrent land use is typically agricultural and willremain as agricultural unless there is informationstating otherwise.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1200-7202.02.02Growth ProjectionsThe Abu Dhabi Municipality’s roadways aredesigned to serve the traffic volume anticipatedduring the next 20 years. Presently, historicalrecords of past growth trends do not exist.Therefore, it is important that a reasonablegrowth projection is used to “size” the project.The growth can be categorized as an increase,decrease or no change. It is anticipated that anincrease will be the most probable scenario in theforeseeable future. The rate of growth can beexpected to increase linearly each year orexponentially (i.e., an order of growth magnitudeeach year).The growth projection can dramatically affectproject “sizing”. Therefore, the Consultant isexpected to develop a realistic growth projectionwhich takes into consideration variables such as:• increases in vehicle ownership• land use• population growth rate, i.e. linear orexponentialIn urban areas, growth projections are dependentupon the rate at which the Town Planning MasterPlan is implemented, as well as the proposedtypes of land use. The Consultant is expected toconfer with the Town Planning Department toascertain the rate at which the Town PlanningMaster Plan is to be implemented.In the rural areas, information regarding growth isless defined. In these cases, it is necessary thatthe Consultant make growth projections. Theseprojections should take into account any dataconcerning growth, including changes in land useadjacent to the roadway. As a starting point, itcan be assumed that the use of land is primarilyagricultural, with an average growth of 1% to 2%per year for a period of 20 years.The resulting growth projection, along withsupporting data and the rationale used tosubstantiate the project, shall be approved by theTown Planning Section.202.02.03Public ServicesThe development of all road and bridge projectstypically affects many public services. This canresult from encroachment of the improvementproject beyond the existing roadway, sidewalk,and bridge. As such, pre-design coordinationwith public services is required to incorporatedesign approaches and construction phasing thatminimize the project impact.The Consultant is responsible for identifying allpublic services which may be affected by theroadway/bridge project. In addition, theConsultant is also responsible to compile allrelevant design requirements from the affectedpublic services and incorporate these parametersinto the project design. It is the Consultant’sresponsibility to assure the Abu DhabiMunicipality that the design and constructionphasing meets the approval of the affected publicservice.Table 200.03 identifies the various PublicServices and the responsible agency/authority foreach.Table 200.03Public ServicesServiceAgency/Authority
Road/BridgeConstructionADM-Road SectionAgriculture/ParksADM-AgriculturePolicePolice Directorate/ Traffic Police Dept.FireCivil Defense Dept.SecurityDefense Dept./CIDSchoolsTown Planning/ Ministry of EducationSanitationADM - Health SectionParkingADM - Road SectionRecreationalTown Planning/ AgricultureNavigable WatersCoast GuardMail ServicePostal DirectoratePublic TransportationADM - Public TransportSection202.02.04SchoolsSchools are an important national resource. Thedesign shall accommodate and preserve sufficientaccess to all facilities that are affected by projectdesign. Therefore, the Consultant is expected to
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1300-1SECTION 300DESIGN CONCEPT REPORT301CONTENTSThe Abu Dhabi Municipality Road Sectionrequires the preparation and approval of a DesignConcept Report (DCR) prior to commencing finalproject design. The report is to be prepared underthe direction of an experienced engineerdesignated by the Municipality. Part 1, Section200, Design Concept Development, includes adiscussion of the background information anddata collection activities necessary to develop thedesign concept. Part 1, Section 300, DesignConcept Report, contains a discussion of thespecific requirements and content of a DCR.The role of a DCR is to summarize the needs,alternatives, costs, and overall impacts of theproposed roadway or bridge project. The scopeof the project is defined and the design criteriaidentified. The DCR is the project scopingdocument and the basis for selecting the projectdesign. The basic roadway configurations shownin the DCR will be carried forward to the finaldesign phase.DCRTable of Contents• Executive Summary• Introduction• Traffic Analysis• Description of Alternatives• Design Data• Typical Sections• Geometrics• Interchange/Intersection Configurations• Parking Study
• Hydrology and Hydraulics• Subsurface Investigations• Bridge Type Selection• Utility Impact Analysis• Socioeconomic Analysis• Agriculture Impact• Public Feedback • Signing and Pavement Markings• Lighting• Construction Staging• Cost Estimate• Conclusion/Recommendations• Drawings, Plans, Profiles, Typical Sections andArchitectural FeaturesThe preliminary engineering activities associatedwith the DCR involve preparation of numeroustechnical studies and reports, many of which areinitiated in the data collection phase as describedin Part 1, Section 200, Design ConceptDevelopment. These are prepared as stand alonedocuments and are included as an Appendices tothe DCR. The DCR will summarize the results of these individual reports under the respective topicincluded in the DCR Table of Contents (See textbox). Furthermore, the discussion under eachtopic will address interdisciplinary relationshipsnecessary to coordinate all
technical aspects of the design concept. The sections that followprovide guidance for the development of thetechnical studies and requirements forpresentation of the material in the DCR.301.01FORMATThe DCR will prepare and packaged as follows:• DCR (Volume I) - Written portion of thereport bound separately in A4 size.• DCR (Volume II) - Drawings that accompanythe report bound separately in A3 size.• DCR (Appendices) -Technical Memorandums, Studies andReports bound in A4 size. For smallerprojects the documents should be boundtogether. Larger projects may requireseparate packaging of the reports, titled asAppendix A, Appendix B, etc.Each document will include the followinginformation on the cover:• Municipality of Abu Dhabi, Road Section• Design Concept Report• Volume No. or Appendix No.• Project Name and Route No.• Project Number• Vicinity Map Schematic with Project Termininoted• Consultant Identification• See Figure 300.01 to be used as the standardcover sheet for the DCR.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1300-2Figure 300.01Standard Design Concept ReportCover SheetLocation / Desin Concet StudProject Location Final ReportProject No.Prepared forAbu Dhabi MunicipalityPrepared byDe Leuw Cather & Co.3875 N. 44thStreet, Suite 250Phoenix, AZ 85018 Preparer’s LogoClient Logo15 May 1997
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1300-3302EXECUTIVE SUMMARYThe Executive Summary is a short (2-4 pages)recapitulation of the DCR document. TheSummary should address the following keytopics:• Purpose and Need of the Project• Alternatives Evaluated• Recommended Design Concept• Major or Controversial Issues• Estimated Cost• ConclusionIt is not necessary to address every aspect ortechnical consideration that is discussed in themain body of the report. The summary shouldfocus on items presented in the report that are of critical interest to the Municipality such as anaccurate concise description of the recommendeddesign concept and the estimated cost. It shouldbe clearly stated how the recommended designresponds to the purpose and need of the project.Both the major benefits (i.e. improve trafficcirculation, improve intersection safety) and theadverse impacts (i.e. displacement of coastalvegetation) should be summarized.303INTRODUCTIONThe introduction is to prepare the reader for thesubject matter that will follow in the body of thereport. It should only be a few paragraphs inlength and should provide a brief description of the project as well as the reason for preparing theDesign Concept Report. The project descriptionshould be very general and should identify theproject’s location, the agency/municipality incharge of its implementation, and the source of funding that will be used for its design andconstruction. A statement can also be includedthat identifies how the project fits into the overalltransportation infrastructure of the area.304TRAFFIC ANALYSISThe collection of traffic data and the trafficprojection procedures are discussed in Part 1,Section 203.03, Traffic Counts. The data will beused to analyze and shape the various alternativesand geometrics. This is an iterative process thatresults in identification of the number of throughlanes, auxiliary lanes, turning lane requirementsincluding storage lengths, signal warrants, level of service and capacity. Schematic diagrams of theroadway segments and intersections should beused to display the data. This information will bepresented in the DCR along with a summary of the project traffic data including
current andforecasted ADT values, peak hour and peak hourdirectional splits and percent of trucks.Traffic signal recommendations will be includedin the report. For each signal location, thefollowing information should be provided:• Phasing Diagram• Controller Equipment• Detection requirements• CCTV• Interconnection• Power SourceOn all projects where the primary justification, oran important justification, of the project is toimprove safety, the DCR should include accidenthistory data and an analysis of the causes of theaccidents as well as a collision diagram.Estimates should be made of the accidentreductions expected if the improvement proposal(or alternatives) is built. The monetary value of the accident savings should be calculated over thedesign period of the project (normally 20 yearswhere geometric improvements are proposed).A summary of the traffic analysis shall beincluded in the body of the DCR. The completereport is also included as a separate Appendix.305DESCRIPTION OFALTERNATIVESIn consultation with the Municipality, theengineer shall develop alternatives to be evaluatedthat respond to the project purpose and need tovarying degrees. The alternatives identified mayinclude separate horizontal alignments, profilevariations, typical section concepts etc., that canbe evaluated in a matrix form to qualitatively andquantitatively review the alternatives to identifymajor differences. The engineering, social,economic and natural environmental impacts foreach alternative under consideration must beaddressed.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1300-4The horizontal alternative alignments will bedisplayed on aerial photographs for evaluation of associated impacts. The sheets will show theproposed centerline, stationing, proposedstructures, edge of pavement lines and affectedproperties, at a scale that is appropriate to theproject length and character.A cost estimate will be prepared for eachalternative and include:• Construction costs• Utility relocation works costs• Land acquisition costsAt this point, meetings will be held with variousMunicipality and Government Departments thathave a vested interest in the project. The engineerwill present the alternatives, review the evaluationcriteria and matrix form and discuss merits andadversities of the different alternatives.Comments and direction received at themeeting(s) will be factored into the alternativesevaluation matrix.Finally, the analysis will conclude with adiscussion of the evaluation criteria for eachmatrix parameter, input/direction receivedconcerning the project and a summary discussionof the advantages and disadvantages of eachalternative studied. This will be followed by theengineer’s recommended alternative withsupporting justification for the selection.306DESIGN DATAThis section will document the design criteriaassociated with the recommended design conceptand specifically identify any exceptions from theminimum criteria established for the roadwayclassification.It is very important that sufficient detail isincluded in the DCR so that future revisions tobasic design features and project scope are held toa minimum.The following basic design criteria established inPart 2, Roadway Design, shall be included: • the functional classification of the road perPart 1, Section 100, General Information.• theminimumdesign speed(s), min.horizontal/vertical curve radii, sight min.distance (passing and stopping), max.superelevation and other design requirementsassociated with theclassification of the road ;•
theactualdesign speed(s), horizontal/verticalcurve radii, sight distance (passing andstopping), superelevation, etc. used for the project ;• lane width, shoulder width, and bridge width;on the project• cross slope;• grade;• horizontal and vertical alignment (actual);• horizontal and vertical clearance; and,• bridge structural capacity.The design exceptions identified shall be preparedin a “Fact Sheet” format as described in Part 2,Section 100, General Design Criteria.307TYPICAL SECTIONSThe typical roadway cross sections and thedimensions of the lanes, shoulders, median(s) forboth the mainline and all ramps are to beidentified. The number of typical sections willdepend on the number of significantly differentroadway/pavement structure conditions. At aminimum, at least one section should be providedwhich depicts all facilities within the limits of theright-of-way (i.e., ramps, frontage roads, drainagechannels, etc.).The type of roadway section, i.e., cut or fill,number of lanes, shoulders, pavement structuralsection, cross slopes, and any retaining walls arealso to be included. Drawings that illustrate thisinformation are to be included in the Appendix tothe DCR.308GEOMETRICSThe alignment, profile, and number of trafficlanes, including through lanes, auxiliary lanes,turning lanes and ramp lanes are to be plotted onan appropriately scaled plan. A scale of 1:500should be used for urban projects and 1:2500 forrural projects. The alignment should be displayedon an aerial base and the corresponding roadwayprofile shown below in a split sheet format.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 1300-5The text in this section should include a narrativedescription of the geometrics, constraints,controlling factors, drainage considerations andreference to the design exceptions. The plans areto be attached as an appendix to the DCR.309INTERCHANGE/INTERSECTIONCONFIGURATIONThe various types of traffic interchanges aredescribed in Part 2, Section 500, Interchanges.The discussion in this section should identify thesite and project considerations which led to theselection of the interchange and intersection type.Thesiteconsiderations include:• the constraints imposed by the existing andnearby transportation facilities• proximity of adjacent interchanges• the standards and arrangement of the localstreet system including traffic control devices• right of way controls• local planning• community impact, and cost topography.The project considerations include:• the speed, volume, and composition of trafficto be served• the number of intersecting legs• crossing and turning conflicts•
safety considerations• costThe interchange/intersection alternatives shouldbe evaluated as a part of the alternatives analysisdescribed in Part 1, Section 305, Description of Alternative, when viable options are identified forthe particular project. This is especially true forfreeway and expressway projects where theInterchange/Intersection type has a significantimpact on the project character, capacity andcost.310PARKING STUDYIn accordance with Part 1, Section 202.09,Parking Requirements, a parking study shall beprepared and included as part of the DCR.The results of the study shall be summarized inthe body of the DCR, with the entire studyincluded in the Appendix.The summary of the results shall include:• the existing parking demand• the anticipated parking demand• the resulting parking shortfall (or excess)• the alternatives as to how the project canprovide adequate parking• cost comparison of parking alternatives• economic impact of inadequate parking• if required by the roadway classification, theneed for off-street parking facilities• the costs and right-of-way requirementsassociated with each of the above alternatives• the recommended alternative to meet theanticipated parking demand,• the conceptual design of the recommendedalternative (see Part 2, Section 211, Parking).311HYDROLOGY ANDHYDRAULICSThe Design Concept Report shall include aseparate section (study) for drainage designconcepts, which shall also include, when required,separate reports for flood plain
encroachment andmajor waterway crossing studies.The drainage design concepts section shalladdress the following items:• Planning consideration for the overallwatershed considering the project and otherexisting and future development • Assessment of existing and future conditionsaffecting drainage areas, flow patterns, andflood levels • Estimate of future development and its effecton flows and flood levels • Drainage map showing topographic features,watershed boundary, slope contours, drainageareas, existing drainage systems, proposedcross-drain locations (including peak flowvolume, design high water elevation andculvert size) and proposed conveyance
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2100-5104.01.03ExpresswaysExpressways are analyzed using a series of nomographs covering a range of average roadwayspeeds. The charts are based on 3.65 m lanes, fullwidth shoulders, and adequate clearances. (SeeHCM Section 100.04.02)104.01.04Expressway Ramps and WeavingSectionsCapacities of urban expressways are influencedby entrance and exit volumes, weave distance,and the geometric layout. All of these factorsshould be considered in the capacity analysis.(See HCM Section 100.04.02)104.01.05Intersection CapacityIntersections capacity generally governs thecapacity of the associated roadway. Signaltiming, intersection spacing, turning movement allplay a critical role in determining the overallcapacity. (See HCM Section 100.04.02)105CONTROL OF ACCESS105.01 GENERALControl of access is achieved by limiting thenumber and location of roadway access points sothat the through traffic capacity or safety of thefacility will not be significantly impaired. Thereare three degrees of access control:Full Access Control- Gives preference tothrough traffic by providing access only throughselected frontage/sector roads and by prohibitingat-grade crossings or direct access from abuttingproperty.Partial Access Control- Still gives preference tothrough traffic but permits some at-gradecrossings and some private drivewayconnections.Approach Road and Driveway Regulations-Without access control, abutting properties arepermitted access to the roadway, but the number,location and geometrics are regulated.Table 100.03Control of Access by Road Type Roadway TypeDegree of Access Control FreewayFull Access ControlExpresswayFull or Partial Access ControlMajor CollectorMain RoadPartial Access ControlMinor ArterialApproach RoadSector Roadand DrivewayLocal RoadRegulationsAll Roadways will have some degree of accesscontrol. The appropriate degree of access controlby roadway type is given in Table 100.03. Moredetailed guidelines for establishing the control of access lines by roadway classification arepresented in the following section.105.02ACCESS CONTROL DESIGNCRITERIA105.02.01Primary RoadwaysThe number of access openings on expresswayswith access control should be held to a minimum.Parcels which have access to another frontage orsector road as well as expressway frontage arenot allowed expressway access. In someinstances, parcels fronting only on theexpressway may be given access to anothersector road by constructing suitable connectionsif such access can be reasonably provided.With the
exception of extensive expresswayfrontages, access openings are limited to oneopening per parcel. Wherever possible, oneopening should serve two or more parcels. In thecase of a large expressway frontage under oneownership, the feasibility of limiting access toone opening may be prohibitive, or the propertymay be divided by a natural physical barrier suchas a wadi or ridge, making it necessary toprovide an additional opening. However, in thelatter case, it may be preferable to connect thephysically separated portions with a low-coststructure or road rather than permit twoopenings.Access rights shall be acquired along interchangeramps to their junction with the nearest publicroad, and shall extend to the end of the ramp taper
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2100-6(or at least 50 m beyond the end of the curbreturn or ramp radius).In remote areas, infrequent access should beaccommodated by providing locked gates. Thiswill only be considered for areas that are remote,infrequently used, and have no other accessmeans. Direct access will not be provided if itcreates an unsafe condition. Turning movementswill be limited to right turns only. Writtenapproval must be granted by the Abu DhabiRoad Section.105.02.02Secondary Roadways,ADT > 2500In general, the number of access openings shall beheld to a minimum for any facility. Additionalaccess may be necessary to satisfy a range of design issues/access requirements. The followingis a list of issues to consider when providingaccess points.(1) Emergency vehicles shall have a right todirect roadway access.(2) Private direct roadway access shall bepermitted only when the property in questionhas no other reasonable access to the localroad system.(3) If feasible, parcels fronting only on theroadway shall be given access to anotherpublic road by constructing suitableconnections.(4) Roadway access openings are limited to oneper parcel. Exceptions may be considered if they do not affect roadway safety oroperation and they are necessary for safe andefficient property use.(5) In certain cases, a natural physical barriersuch as a wadi or ridge may divide the parcel.In this case additional access openings maybe warranted. However, it may be preferableto connect the physically separated portionsof the parcel with a low cost structure or roadrather than permit multiple access openings.(6) Wherever possible, one access opening shouldserve two parcels.(7) When the number of required access openingson one side of a divided roadway exceedsthree in 400 m, a frontage/sector road shall beprovided. See Section 105.03, Use of Frontage Roads, for further discussions.(8) Access openings on divided roadways shallnot be permitted within 100 m of a medianopening unless the access opening is directlyopposite the median opening.(9) Access approaches shall be limited to rightturns only unless (1) the approach has nosignalization potential and allowing left turnswould significantly reduce congestion andsafety problems at a nearby intersection; or(2) there are no intersections, existing orplanned, that allow a U-turn; and (3) leftturns can be safety designed withoutsignalization.(10)
Access approaches with signalizationpotential and that require left turn movementsmust (1) meet the signalization requirementsas specified in Part 2, Section 902,Signalization, and (2) shall not interfere withthe location, planning, or operation of thegeneral road system and nearby propertyaccess.105.02.03Secondary Roadways,ADT < 2500The primary function of these roadways is toprovide reasonable and safe access to abuttingproperty. Access needs generally take priorityover through traffic as long as roadway safety isnot compromised. Control of access is notobtained, but the location, number, andgeometry’s of access points must meet thefollowing criteria:(a) The number of access approaches to a parcelshall be controlled by safety and designconsiderations and shall be separated by atleast the stopping sight distance.(b) For safety reasons, frontage roads or parallelservice roads are not permitted along two-lane roadways because this results in theappearance of a divided roadway.(c) Left turns if safety and design standards aremet.(d) In rural areas, approach roads shall beprovided as necessary for local access oremergency/rest stops. The maximum spacing
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2100-7between approach roads shall be 5 km forthese purposes. (e) In urban areas with signalized intersections,the minimum spacing between access pointsshall be that which is necessary for the safeoperation and proper design of intersectionsas specified in Section 400.105.03USE OF FRONTAGE ROADS(1)General Policy(a)Frontage roads are provided:• To control access to the urbanexpressway and main roadthrough lanes, thus increasingsafety.• To provide access to sectors.• Maintain continuity of the localroad systems.• Provide for non-motorizedtraffic that might otherwisedesire to use the expressway.(b)Typically a frontage road is justified if their construction costsare less than the costs of providingother direct access. Right of wayconsiderations are often thedetermining factor. Thus, afrontage road would be justified if the investment in construction andextra right of way is less thaneither the severance damages orthe costs of acquiring the affectedproperty. Frontage roads may berequired to connect parts of asevered property or to serve alandlocked parcel resulting fromright of way acquisition.(c)Direct access to the through lanesis allowable on expressways.However, when the number of access openings on one side of theexpressway exceeds three in 500m, a frontage road should beprovided.(2)New Alignment.Sector roads generallyare not provided on new expresswayalignments since the abutting propertyowners never had legal right of access tothe new facility. They may be provided,however, on the basis of considerationsmentioned above.(3)Existing Alignment.Where an expresswayis developed parallel to an existingroadway or local road, all or part of theexisting roadway is often retained as afrontage or sector road. Frontage roadsmust be constructed to serve landlockedremainders or the remainders must bepurchased outright if other means of access cannot be provided. The decisionwhether to provide access or purchaseshould be based on considerations of cost,right of way impacts, road systemcontinuity and similar factors discussedabove.105.04PROTECTION OF ACCESSRIGHTS
Access Control lines/limits shall be shown on theproject right-of-way plans. Where possible, theright-of-way line and control of access lineshould be coincident.For proper control of access, fencing or otherapproved barriers shall be installed on allcontrolled access roadways, located on thecontrol or access line where appropriate.106DESIGN STANDARDEXCEPTIONSA design standard exception is a design featurewhich does not meet the design standardspresented in the Roadway Design Manual.Occasionally these design exceptions are justifiedbut it is important that each design exception bedocumented and approved in writing prior to planacceptance.The request for approval of design exceptionsshall be in the form of a Design ExceptionRequest. This request sheet shall be presented tothe Municipality for written approval. Therequest sheet shall include the following topics:
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2100-8• Proposed Project• Existing Roadway• Proposed Design Exception• Additional Cost To Comply WithStandards• Incremental Improvements• Supportive DataA detailed description of the items required in theDesign Exception Request sheet is included on thefollowing pages.DESIGN EXCEPTION REQUEST SHEET1.PROPOSED PROJECTA. Project Description: Briefly describe theproject. Note the type of project and/ormajor elements of work to be done, suchas safety or operational improvement,roadway widening, rehabilitation,reconstruction, etc. Provide thegeographic project limits and length. B. Proposed Project Total Cost: Include aestimate of the proposed project costsegregated by major elements, including:roadway, structures, right of way, utilityrelocation, environmental mitigation, etc.,as needed.2.EXISTING ROADWAYA. Existing Roadway Description:Describe the existing roadway featuresrelevant to the proposed design exception.This may include such things as thewidths of lanes, shoulders, median, clearzones, roadbed,
and structures;horizontal and vertical alignment andclearances; design speed, sight distance,grades, cross slope, superelevation, etc. If relevant, provide a similar brief description of adjacent existing roadwaysegments, noting existing nonstandardfeatures.3.PROPOSED DESIGN EXCEPTIONA. State the specific design standard(s)which are not being met and refer to their Roadway Design ManualPart andSection number(s). B. Describe the proposed design exceptionor the existing design exception which isproposed to be maintained. If proposed,state whether the design exception is animprovement over the existing condition.Describe proposed improvements thatwould qualify as safety enhancementsover the existing condition, such as:median barrier, guardrail upgrade,flattening slopes, correctingsuperelevation, eliminating roadsideobstructions, etc. C. Provide a thorough brief justification forthe design exception. Reasons forgranting design exceptions include acombination of excessive cost, right of way impacts and/or environmentalimpacts. Supportive factors haveincluded low accident frequency, localopposition, and consistency with adjacentroadway segments.4.ADDITIONAL COST TO COMPLYWITH STANDARDSProvide a realistic estimate of the additionalcost required to meet the design standard forwhich the proposed exception is requested.5.INCREMENTAL IMPROVEMENTSDiscuss other practical alternatives that areintermediate in scope and cost between theproposed project (requiring this designexception) and the full, standard solution.Provide enough information on costs versusbenefits, right of way and environmentalimpacts, etc., to explain why none of theincremental alternatives are recommended.These alternatives should normally beinvestigated prior to requesting an exception.6.SUPPORTIVE DATAA. Traffic Data: Provide both ADT’s andDHV (design hourly volumes). Usedesign year traffic.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2100-9B. Accident Analysis: Safety is of primaryimportance when considering designexception approval. If relevant, includean accident data analysis to identifyprevalent accident types and causes, plusan evaluation of the effect of therequested design exception on accidenttypes and frequencies. C. Attachments:1.Provide a location or vicinity mapfor the project.2.Provide plan sheets, cross sections,profiles and/or special details toclearly illustrate the proposeddesign exception.3.Attach pertinent letters,resolutions, meeting minutes,studies, etc., which further developor clarify the proposed designexception.107BICYCLE FACILITIES107.01GENERALThe bicycle has become an important element forconsideration in the highway design process.Fortunately, most of the mileage needed forbicycle travel is comprised of the street andhighway system. While many highway agenciesallow bicycles on partially access controlledfacilities, most highway agencies do not allowbicycles on fully access controlled facilities.Measures such as the following, which aregenerally of low capital intensity, canconsiderably enhance a route’s safety andcapacity for bicycle traffic:• Paved shoulders.• Wide outside traffic lane (4.2 m minimum) if no shoulder.• Bicycle-safe drainage grates.• Adjusting manhole covers to the grade.•
Maintaining a smooth, clean riding surface.For further information and guidelines onbicycles, refer to the latest edition of AASHTO,Guide for Development of Bicycle Facilities.107.02SPECIAL BICYCLE FACILITIESAt certain locations or in certain corridors, it isappropriate to supplement further the existinghighway system by providing specificallydesignated bikeways (for either exclusive or non-exclusive bicycle use). Rural arterials often arethe only direct connection between areas of population and locations to which the publicwishes to travel, Schools, parks, and ruralhousing developments are usually located to bereadily accessible by automobile. However,pedestrians and bicycle riders may also wish totravel to the same destination points. When sucha situation exists, the designer should consider theeffects on the safety and operation of the arterial.A special effort should be made to provide thegreatest degree of safety within the economicconstraints that must always be considered.107.03BICYCLE CHARACTERISTICSTo provide for bicycle traffic, it is necessary tobecome familiar with bicycle dimensions,operating characteristics, and requirements.These factors determine acceptable turning radii,grades, and sight distance. In many instancesdesign features of separate bike facilities arecontrolled by the adjoining roadway, so that eventhen consideration of bicycles is an essentialelement the design of the highway itself.107.04BICYCLES ATINTERSECTIONSWhen on-street bicycle lanes and/or off-streetbicycle paths enter an intersection, the design of the intersection should be modified accordingly.This may mean special sight distanceconsiderations, wider roadways to accommodateon-street lanes, special lane markings tochannelize and separate bicycles from rightturning vehicles, provisions for left turn bicyclemovements, or special traffic signal designs (suchas conveniently located push buttons at actuatedsignals or even separate signal indication forbicyclists).
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2200-19• Required for proper drainage.• Needed for channelization, delineation,control of access, or improving traffic flowand safety.• To protect pedestrians and provide continuityat ramp connections with local roads.• To replace existing curbs.• To protect the expressway fence on frontageroads where required.209.02TYPES AND USESCurb types and uses are shown in the currentStandard Drawings and are discussed below.Precast Curb Type A, B, C -These curbs areused to deter vehicles from using areas outside thetravelled way, control drainage, and regulate andcontrol parking. Type A curbs are typically usedon the outside of the travelled way, adjacent tosidewalks and parking lanes. Typical B and Ccurbs are used at the median edge adjacent to thegreen area.The above curb types are classified as barriercurbs and are not generally used on high-speedroadways as they present a safety hazard forerrant vehicles. A continuous concrete barrier(safety shape) should be used where it isnecessary to control drainage or access on high-speed roadways.Cast-In-Situ Concrete Curb Type D -This curbis flush with the pavement and used to separatethe travelled way from interlocking vehicularpavement.Precast Concrete Curb Type E -This curb isused between interlocking pedestrian pavers andgreen or service reservation areas.Cast-In-Situ Concrete Curb Type F -This curbis flush with the pavement and used to separateinterlocking pedestrian pavers from quarry tile.209.03CURB PARAMETERSPlacement -Curbs should be positioned toprovide the same unobstructed roadway widththat is normally provided. All curb dimensions areto the inside face of curb.Transitions -A transition from one curb type toanother shall be done in 3.0 m. At curb termini,the curb should transition from normal curbheight to zero in 5.0 m.210BUS STOPS AND TAXI STOPS
In urban areas, bus stops and taxi stops will beprovided on all main roads.To prevent ponding in bus and taxi stops on flatgrades use either a reverse cross slope toward themain road pavement with slotted trench drains orcontinue the slope of the roadway and install aninlet along the loading/unloading curb line.210.01BUS STOPSBus stops will be located at the far side of intersections and as necessary at midblock locations. Near side bus stops should be avoided.Normally, bus stops shall be constructed asshown on the current Standard Drawings. Underrestrictive conditions these standards may bereduced to 15.0 m length, 10.0 m tapers and 3.25m width.At all bus stops a 4.0 m wide sidewalk shall beprovided along the loading/unloading area. Thisshall be connected to the nearest sidewalk with a4.0 m wide perpendicular sidewalk.210.02TAXI STOPSTaxi stops will be located at the far side of intersections, no closer than 30.0 m to the radiusreturn or end of right turn taper. Taxi stopsshould be located as necessary within the block but no closer than 30.0 m to a sector road.Taxi stops shall be constructed as shown on thecurrent Standard Drawings. At all taxi stops a 4.0m wide sidewalk shall be provided along theloading/unloading area. This shall be connected tothe nearest sidewalk with a 4.0 m wideperpendicular sidewalk.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2200-20211PARKINGTo maximize the effective capacity of expresswayand main road improvements, sufficient off-system parking facilities should be provided toavoid the need for curb lane parking alongprimary expressways and main roads.211.01GENERALParking facilities are of four general types:1.Parking areas located parallel to, butphysically separated from, main roadmoving traffic lanes,2.On-road parking spaces developedadjacent to the travelled lanes of sectorroads, and3.Independent parking lots developed off sector roads.4.Parking Structures.Each facility consists of an “aisle” area and a“standing area” (parking stalls). In the case of on-road parking, the moving lanes of the sector roadalso serve as the aisle.Figure 200.11 illustrates different forms of thebasic types of parking facilities.211.02PARKING AREASLots P1 and P2 on Figure 200.11 are typical“parking areas,” characterized by one entranceoff the main road, then an aisle area with adjacentperpendicular and/or 45 degree parking, andfinally an exit leading back onto the main roadtravel lanes. Desirably, the entrances and exitsshould be independent of any sector road or mainroad intersections (i.e., Lot P2). When physicalconditions prevent this, a common entrance (orexit) may be an acceptable arrangement (i.e., LotP1).The minimum safe distance from a main roadintersection to a parking entrance or exit will bedependent on many factors, such as, volume andspeed of the traffic, type of intersection, widthand number of lanes in the main road, the volumeof traffic using the parking area, and any sightdistance restrictions.Generally it is desirable to locate parking exitsonto main roads about 50 meters prior to the startof the left turn storage lane, and parking entrancesoff of main roads about 60 meters prior to theintersection, and/or prior to the start of the freeright turn taper.In the typical case, a “parking area” is physicallyseparated from the main road lanes by acurb/sidewalk/curb combination which has beendesignated as a “wide curb”. See Lot P2 in Figure200.11. The minimum distance between the facesof the two curbs is 1.0 m.The parking area edge nearest the buildingsshould be set parallel to the building line and at asufficient offset distance to allow a sidewalk along the building line.The current Standard Drawings illustrate typicalparking area and show stall dimensions andpavement markings for both perpendicular and45-degree parking arrangements. Aisle widths andstall depths should be as per Table 200.08.Table 200.08Parking Isles and Stall Depths Parking Aisle WidthStall Depth Angle (m)(m) AbsoluteDesirableAbsoluteDesirable MinMinMinMin90o7.07.35.55.860o5.05.55.76.045
o4.55.05.35.6211.03ON ROAD PARKING SPACESParking spaces along sector roads are developedby constructing added pavements immediatelyadjacent to the sector road moving lanes (usuallytwo lanes with one lane for travel in eachdirection). Such parking spaces should be eitherparallel or perpendicular. The use of 45-degreeparking should be limited to one-way sectorroads.Figure 200.11 shows examples of on-roadparking space developments along sector roads.Dimensions for perpendicular and 45-degree
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2200-21parking stalls are similar to those given on theStandard Drawings.Parallel parking stalls should have a length of 7.0m and a desirable minimum width of 2.5 m asshown on the Standard Drawings.Where sector roads are widened to provideparking stalls, the widened sector roadarrangement should not be carried through sectorroad/sector road intersections. The fillets at suchintersections (usually 5.0 m radii) should bepositioned to line up with the edge of the travelledlanes.211.04PARKING LOTSFigure 200.11 also shows samples of independentparking lots developed off sector roads. Such lotsare of two general varieties:1.Single entrance/exit (see lots P3, P4 and P5)and2.Double entrance/exit (see Lots P6 and P7).Wherever practical, these layout rules should befollowed:1.Aisles and entrance/exit widths should betypically designed for two-way operation inconjunction with perpendicular parking.2.A median (curb/sidewalk/curb combination)at least 1.0 m wide should be providedbetween adjacent parking bays served off different aisles (i.e., on Figure 200.11, abarrier is provided between Lots P6 and P7).3.Forty-five degree parking should only be usedin conjunction with one-way aisles/sectorroads.211.05PARKING DEMAND/SUPPLYANALYSISDuring the early portion of the Concept DesignPhase, the designer will:1.determine the location of existing parkingfacilities,2.identify any facilities to be displaced by roadimprovements that should thus be replaced,and3.determine the need for added parking facilitiesand establish an approximate location forsuch parking.The required analysis regarding parking will thusvary from project to project since parking demandis sensitive to site-specific factors, such as landuse and proposed community developments.In the absence of site specific parking criteria,Table 200.09 should be used. Also refer to Part 1,Section 202.02.11 for further parkingrequirements.Table 200.09Parking Requirements Type of DevelopmentParking RequirementsCommercial/Office1 space / 50 m2floorspaceRetail1 space / 30-50 m2floorspaceGovernmental1 space / 50 m2floorspaceSchool1 space / 3 employeesplus1 space / 5 studentsHospital1 space / 2 employeesplus1 space / 4 bedsLow DensityResidential Villas2 spaces / dwelling unitMedium DensityApartments1 space / (100m2*.85*.80)High DensityApartments1 space / (100m2
*.85*.80)These requirements should be considered asminimums.It is possible that the number of spaces requiredby these guidelines cannot be provided due tospace limitations. In that case, efforts should bedirected toward providing the maximum amountof parking in a reasonable configuration.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2200-22Figure 200.11Typical Parking Facilities
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2300-1SECTION 300GEOMETRIC CROSS SECTION301TRAVELLED WAY STANDARDS301.01TRAVELLED WAY WIDTHTravelled way width is one of the most importantsafety factors in design. A wide two-lane two-waypavements provides higher capacity, higher drivercomfort levels, consistent operation and loweraccident rates.Minimum travelled way widths of 7.30 m shall beprovided on all design classes of roadways.Traffic lane widths shall be 3.65 m, and thenumber of lanes required shall be based on theprojected traffic volume and roadwayclassifications. Loop ramp lanes shall be 5.0 m.See Section 302 for general shoulder widths andsee Section 305 for specific roadway crosssection widths.301.02TRAVELLED WAY CROSSSLOPESTangent cross slope is balanced between steepcross slopes, desirable for drainage and the factthat vehicles drift toward the lower pavementedge on steep cross slopes. Generally, crossslopes below 1.5 percent have little effect onvehicle steering. Cross slope values for thevarious roadway classifications are provided inthe following sections.Unpaved travelled ways shall have a cross slopeof 3.0 percent.See Section 305 for specific roadway cross sloperates.Pavement superelevation on curves shall be asdetermined in Section 202.302SHOULDER STANDARDSShoulders provide pavement structural support,improve sight distance, provide emergencystopping areas, and help provide required sideclearance. However, shoulders are unnecessary onmost urban roads because curbs providepavement structural support, and disabledvehicles can park in parking lanes, side streets, ordriveways.302.01SHOULDER WIDTHSTANDARDSTable 300.01 summarizes the minimumcontinuous usable width of paved shoulder forvarious roadway classifications.Table 300.01Paved Shoulder Width Standards RoadwayInsideOutsideClassShoulderShoulder / verge/ verge(m)(m)RURALFreeway3.04.0/2.0Expressway3.04.0/2.0Collector-2.4Local Access2.0URBANFreeway3.04.0/2.0Expressway3.04.0/2.0Arterial (Main Rd)-4.0/2.0Frontage Road1.21.2Sector Road--2-LANE RAMP2.4/2.03.0/2.0LOOP RAMP2.0/1.03.0/1.0The verge is the area outside the paved shoulder,usually rounded, at the top of embankment slopes.302.02SHOULDER CROSS SLOPESIn normal tangent sections, inside shoulder slopeshall match the travel lanes and outside shouldersshall slope on a 3% grade away from the travelledway.303SIDE SLOPE STANDARDSProperly designed side slopes insure roadwaystability and provide a safe recovery area forerrant vehicles.Where feasible, slopes should be flattened to beconsistent with the roadway classification andtopography. The tops and ends of all slopes
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2300-2should be rounded 3.0 m where the material isother than solid rock.303.01SIDE SLOPE VALUESSide slopes should be 1:6 or flatter depending onsoil type. If slopes are steeper than 1:3, barriermay be required. Earth cut slopes should be atleast 1:3 but in no case steeper than 1:2.303.02SLOPE CLEARANCE FROMRIGHT OF WAYThe minimum clearance from the right of way lineto the catch point should be 3.0 m with 4.5 mdesired. For cut slopes this is measured from theouter edge of the rounding or crown drainagesystem. Slopes over 15.0 m high may requireadditional clearance for maintenance.304MEDIAN STANDARDSA median is the portion of a divided roadwaybetween the opposing travelled pavements.Raised medians shall be used on urban roads toregulate left-turn movements. Paved medians,including those bordered by curbs, should becrowned at the center, sloping towards the sides atthe slope of the adjacent pavement.Unpaved, landscaped medians between curbsshall be graded flat. Other unpaved mediansshould slope downward from the shoulders toform a shallow valley. Cross slopes should be1:10 or flatter 1:20 being preferred. Slopes assteep as 1:6 are acceptable if necessary fordrainage.See Section 305 for specific roadway medianrequirements.305CROSS SECTION ELEMENTSSee Figure 300.01 for typical cross sections of various roadway classifications.Pavement Structure -For the StandardPavement Structures, see current StandardDrawings. Also, refer to Section 604 StructuralPavement Section Design.Shoulders -Shoulder widths for various roadwayclassifications are summarized in Table 300.01.305.01RURAL FREEWAY/ EXPRESSWAY CROSSSECTIONGeneral -The typical section for ruralexpressways shall be comprised of two roadwayswith shoulders, divided by a median.Travelled Roadways -Each roadway willconsist of a minimum of three 3.65 m throughlanes. Ramps shall be 5.0 m for one lane and,where volumes demand, two 3.65 m lanes.Median -Median treatment may be eitherstandard concrete barriers placed along the insideshoulder edge or an unpaved depressed median.Median width may vary to match existing medianwidths. The width of the depressed medianmeasured between edges of travelled pavementshall be 20.0 m minimum.Cross Slope -Except superelevated sections, auniform cross slope of 1.5 percent shall beapplied across the inside shoulder and drivinglanes. The outside shoulder will have a cross-slope of 3.0 percent. The pavement will slopetoward the outside of the section.On structures, the cross-slope shall be 1.5 percentuniformly across the inside shoulder, drivinglanes, and outside shoulder.
Profile Grade Line -The profile grade line shallbe at the median edge of the travelled roadway.305.02URBAN FREEWAY/ EXPRESSWAY CROSSSECTIONGeneral -The typical section for urbanexpressways shall be comprised of two roadways,with shoulders, divided by a median. Due to spacelimitations, the cross section may vary. The finalconfiguration shall be determined during theconcept phase of design.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2400-13406.03EFFECT OF VERTICALPROFILESA vehicle descending a grade requires greaterstopping distance than one on level ground.Conversely, a vehicle ascending a grade requiresless distance to stop. Grades up to 3 percent havelittle effect on stopping sight distances. In no caseshould the grades exceed 6 percent.For Stop Controlled intersections, the timerequired to cross a roadway is affected by thecrossing grade. If the grade is significant, thesight distance should be increased.Where the intersection leg grades are other thanflat, corrections should be made to the sightdistances using the approximate ratios given inTable 400.02.Table 400.02taAdjustment For GradeSight Triangle Distances Ratio, t a on grade / t alevel (Figure 400.05)Crossroad Grade %Design Vehicle-4-2024P0.70.91.01.11.3SU0.80.91.01.11.3WB-150.80.91.01.21.7Use this table to adjust t avalues for effect of grade. Based on the likely range of crossingdistances.406.04LEFT-TURNCHANNELIZATIONGeneral -A left-turn lane expedites throughtraffic flow, controls turning traffic movement,and improves the intersection safety and capacity.The left-turn lane should be laid out such that theturning vehicle must make a definite move toenter the lane. The desirable length of the left-turnlane is the sum of the required storage length anddeceleration length, including the bay taperlength.Width -The desirable left-turn lane width shouldbe 3.65 m. Three meter wide left-turn lanes maybe used on low speed urban roadways. The widthis measured from the adjacent edge of travelledway, excluding shy distance.Medians -To improve left-turn visibility, the left-turn-lane should be placed as far to the left aspossible in the median leaving only the painted orcurbed nose. Excess width between the left-turnlane and the adjacent same-direction through laneshould be treated as painted island. When left-turn lanes are placed in raised (curbed) medians,a minimum nose width of 1.0 m should remain forpedestrian refuge and traffic control devices.Approach Tapers -On roadways with narrow orno medians, room for the left-turn lane is made byshifting traffic laterally to the right. The taperlength used to effect this shift should be 0.6WV,where W = lateral shift (m) and V = design speed(kph).
Bay Tapers -The bay taper length should beshort to clearly identify the additional lane.Generally the taper length should be 15:1.Deceleration Length -Whenever feasible, theleft-turn lane should provide deceleration clear of the through lanes. The minimum decelerationlengths, exclusive of bay taper and vehiclestorage, for 50, 60 and 80 kph are 70, 100 and130 m, respectively.In urban areas, it may not be possible to providethe deceleration lengths and maintain the storageand approach taper lengths required. In thesesituations, these lengths should be used as adesirable goal.Storage Length- The storage length should besufficient:• To store the number of vehicles duringcritical periods.• To avoid left-turning vehicles stopping in thethrough lanes.• So the lane entrance is not blocked bystanding through traffic.Refer to the “Highway Capacity Manual, SpecialReport No. 209”, Transportation ResearchBoard, 1986 for further discussion.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2400-14406.05RIGHT-TURNCHANNELIZATIONGeneral -Right-turn lanes improve intersectioncapacity and safety. As for left-turn lanes, right-turn lanes should be laid out such that a right-turning vehicle must make a definite move toenter the lane.The desirable length of the right-turn lane is thesum of storage requirements and decelerationlength, including bay taper.Width -The desirable right-turn lane widthshould be 3.65 m. Three meter wide right-turnlanes may be used on low speed urban roadways.The width is measured from the adjacent edge of travelled way, excluding shy distance.The normal shoulder should be provided at theright-turn lane although, if right of way isseverely constrained, a minimum 1.2 m wideshoulder may be used. The normal curb should becarried through the right-turn section.Approach Tapers -Generally right-turn laneapproach tapers are not required because the laneis added to the outside of the travelled way andthe travel lanes are not shifted. However, if thetravel lanes must be shifted to accommodate aright-turn lane, the taper should be the same asfor left-turn lanes.Bay Tapers -The bay taper which guides themotorist into the right-turn lane is a straight linealong the right edge of the travelled way.Generally the taper length should be 15:1.Deceleration Length -Whenever feasible, theright-turn lane should provide deceleration clearof the through lanes. The minimum decelerationlengths, exclusive of bay taper and vehiclestorage, for 50, 60 and 80 kph are 70, 100 and130 m, respectively.In urban areas, it may not be possible to providethe deceleration lengths and maintain the storageand approach taper lengths required. In thesesituations, these lengths should be used as adesirable goal.Storage Length- Storage requirements and goalsare the same as for left-turns.Free Right-Turns -Uncontrolled “free” right-turns improve capacity of an intersection with aheavy right-turn demand. The right-turn is made"free" by channelizing the turning movementoutside of the intersection controls. Free right-turns shall only be provided where the turningmovement can be made into an auxiliary oracceleration lane.406.06TRAFFIC ISLANDSGeneral -Traffic islands are located betweentraffic lanes and are commonly designated usingpaint, raised pavement markers, or curbs. Theyserve to:• confine specific traffic movements intodefinite channels;• separate traffic moving in the same oropposite direction;•
aid and protect pedestrians crossing theintersection; and,• discourage or prohibit undesirablemovements.Design -Traffic islands must be large enough tobe seen and to command the attention of thedriver. Islands for channelizing should preferablybe at least 9.0 m2. Curbed islands for separatingtraffic streams should not be less than 1.0 m wideand 8.0 m long.Curbed islands should be offset from the throughtraffic lanes by a minimum shy distance of 0.6 mand 0.9 m is preferable for approach speedsgreater than 25 kph.The approach end of a curbed island should berounded at 0.5 to 1.0 m radius and tapered at 15:1to guide the driver into the channelization.Where there is an approach shoulder (1.2 m orwider), the curbed island should be offset fromthe through lane by the width of the shoulder.With an approach shoulder the flared approach isnot necessary, except where a deceleration orturning lane has been provided.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2400-15Avoid curbed traffic islands where the approachoperating speeds are 80 kph or greater.Mountable curbs should be used at curbed islandsexcept where barrier curbs are provided forgreater pedestrian protection.407ROUNDABOUT DESIGNThere are three main types of roundabouts,Normal, Mini and Double. There are other formsof roundabouts but they variations of these basictypes. They are Ring Junctions, Grade Separatedand Signalized Roundabouts. More informationabout the use and design of these and otherroundabouts can be found in theGeometric Design of Roundabouts. When reading thisdesign manual the designer should be aware thatthe manual was written for left-hand runningtraffic and appropriate modifications should bemade for when adapting these standards to right-hand running traffic patterns.The roundabout is used at intersecting streets withlow capacity and low design speed. Roundaboutsshould be considered when they are cost effectiveor increase safety over standard intersectiondesigns.Advantages:There are several advantages toroundabout design versus conventional three andfour leg intersections.• Roundabouts are more efficient than signalson balanced traffic demand intersections.• Roundabouts allow for continuous trafficflow.• Roundabouts can reduce traffic speeds inexisting intersections.Disadvantages:There are several disadvantagesto roundabouts that make them less favorablethan conventional designs.• Driver comprehension to right-of-way withrespect to yielding to traffic flow.• Roundabouts are prone to large congestionproblems when traffic exceeds designcapacity.• It is difficult to redesign an existingroundabout to increase its capacity. Redesignrequires adding more lanes which greatlyincreases the land required for theintersection. This increase in diameter alsoincreases the design speed through theroundabout. For these reasons roundaboutstend to be removed and replaced withconventional signalized intersections insteadof being modified.
• Roundabouts require more land thanconventional intersections.• Roundabouts are not well suited forpedestrian traffic, because pedestrians are notable to walk in a clear path through theintersection. In areas of high pedestriantraffic, pedestrians can cause major problemswith illegal crossings.Normal Roundabouts:The normalconfiguration of a roundabout is made up of aone-way road around a circular curbed island 4mor more in diameter. The approaches are usuallyflared to allow multiple vehicle entries. Thenumber of entries should be limited to three orfour arms. The efficiency and drivercomprehension decreases as the number of armsis increased. The minimum radius of curvaturealso increases with additional arms which canraise circulatory speeds. Double roundabouts canbe an alternative under these conditions. SeeFigure 400.08.Figure 400.08Normal RoundaboutMini Roundabouts:The mini-roundabout issimilar to the normal roundabout except thediameter of the island is less than 4m. Instead of a curbed island a raised, reflectorized dome isused for driver recognition of the high spot. Themini-roundabout is a good alternative for existingroads with extremely low traffic volumes thathave high safety and delay problems. Wherephysical deflection of approaching traffic is not
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2400-16possible, roadway stripping and traffic islandsmay be used. See Figure 400.09.Figure 400.09Mini RoundaboutDouble Roundabouts:Double roundabouts aregenerally used in areas with unique trafficrequirements such as:• Where intersection improvements are doneand the roundabout eliminates the need torealign an approach road.• In areas where more than four arms areentering the intersection.• At intersections with unusual or asymmetricalconfigurations.• Where single island configurations do nothave enough capacity.• The joining of parallel roads separated by anexisting feature.These unique circumstances should be evaluatedby an experienced traffic engineer and theMunicipality must be informed on the decision toconsider a double roundabout. The doubleroundabout should only be used after properconsideration and is contingent only with theapproval of experienced personnel and theMunicipality. See Figure 400.10. Figure 400.10Double Roundabout
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2500-1SECTION 500INTERCHANGES501 GENERALThe ability to accommodate high traffic volumessafely and efficiently through intersectionsdepends on how intersecting traffic is handled.The greatest efficiency, safety, and capacity areattained when intersecting through traffic lanesare physically separated. An interchange doesthis with a combination of ramps and gradeseparations at the junction of two or moreroadways. This reduces or eliminates trafficconflicts, improves safety, and increases trafficcapacity. Crossing conflicts are eliminated bygrade separations and turning conflicts areeliminated or minimized depending on theinterchange configuration.The selection and design of grade separationsand interchanges is influenced by roadwayclassification, traffic volume, traffic composition,design speed, access control, signingrequirements, economics, terrain, right-of-way,capacity and safety. Interchange types varywidely so each site should be studied andalternate concepts made to determine theappropriate layout.502 INTERCHANGE WARRANTSInterchanges are very costly and should be usedonly where necessary. Interchanges should beconsidered based on the following warrants:• Where intersecting traffic volumes areheavy.• Where topography does not lend itself to theconstruction of an intersection.• When making a connection to a freeway.• For a roadway with access control betweenselected terminals.• To eliminate a traffic bottleneck.• To eliminate a hazardous at-gradeintersection.• When road-user benefits are substantial.503 DESIGN CONSIDERATIONSDue to the complex nature of interchange designit is important to establish a set of consistentdesign parameters. Listed below are featureswhich should be considered during theinterchange design process.•
Provide consistent design features.• Ramp exits shall be from the right.• Ramp entrances shall be on the right.• One exit per direction from main roadway.• Ramp design speed beyond exit shouldpreferably be one-half to two-thirds that of the roadway.• Provide ramps for return or complementarytraffic movements at same interchange.• Use grades and slopes as flat as possible.• Consider signing during geometric design.504 INTERCHANGE TYPESThis section includes examples of commonlyused interchange configurations. See Chapter Xof "A Policy on Geometric Design of Highwaysand Streets," AASHTO, 1994, for additionalexamples.504.01 THREE-LEG INTERCHANGEThree-leg interchanges have three intersectinglegs. They usually consist of one or moreroadway grade separations and one-wayroadways for all traffic movements. Becausefuture expansion is difficult, three-leginterchanges should only be used when one of the three legs is permanently terminated. Heavytraffic volume should be favored with moredirect alignments, and lesser volumes can belooped. Skewed crossings are desirable becausetravel distance is less, the turning radius is flatterfor the heavier left-turning volume and there isless angle of turn for both left turns.Figure 500.01 illustrates several types of threeleg interchanges.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-10904.05ARABIC LETTERING FOR GUIDESIGNS904.05.01GeneralGuide signs shall be designed in Arabic andEnglish, with the Arabic message above theEnglish translation. To size the signs, the actualwidth of the Arabic and English messages mustbe determined.904.05.02The Arabic AlphabetThe first letter in the Arabic alphabet is “aleph”which is a simple downstroke. For the purposes of the Standard Script, aleph is used to proportionthe height of the letters. In developing theStandard Script, it has been determined that analeph height of 30 cm generally corresponds tosigning on freeways, while an aleph height of 24cm corresponds to signing on arterial roads.Figure 900.05 provides spacing criteria for GuideSign design. Figures 900.06 through 900.17 aretemplate guides for Arabic letters and numerals.When designing guide signs for all Abu Dhabiroadway projects, signs to be read from freewaysand expressways will have 30 cm (aleph height)Arabic lettering and 27 cm English lettering.Signs to be read from ramps and main roads willhave 24 cm (aleph height) Arabic lettering and 20cm English lettering.904.05.03Use of the Standard Arabic ScriptThe shape of each letter and number in theStandard Script is shown on a five-millimeter gridin Figures 900.06 through 900.17.To get the actual width of a word on the guidesign, find the width of each letter shape in theStandard Script. Then multiply that width by theproportion of the aleph height in the final guidesign to the aleph height shown in the Script.Finally, add the width of each letter shape, takinginto account the spacing rules for unconnectedletters to obtain the total message width.Arabic lettering is aligned on a baseline, just as inEnglish. The location of the baseline for eachletter is indicated by an arrow (V) adjacent to thatletter in the Standard Script. Some letters extendquite a distance below this baseline; therefore, thevertical spacing on the sign face should bechecked and adjusted, if necessary.The width of the message “Corniche Road” iscalculated in Example 900-01 on the followingpage. The page numbers refer to the fourteenpages in the Standard Arabic Script for HighwaySigns, Section 904.07. Aleph height was assumedto be 24 cm, slightly larger than the English 20cm lettering. Calculations proceed right to left.Looking at the last letter in the first word, theshape extends 43 mm below the baseline. Usingthe proportion of 4.8, at least 20.64 cm will berequired between the Arabic and English messageto avoid conflict.904.06GUIDE SIGN DIMENSIONS904.06.01Single Message Guide Signs(Example 900-02)After computing the preliminary sign width(message width, arrow width, and offsets) it shallbe rounded to the nearest 5 cm to get the finalsign width. Changes to the adjustable basedimensions most likely will have to be made toachieve this.Sign faces shall be detailed as per the theoreticalheight dimensions for a particular sign. Smallvariations in the spacing between the legend andthe border can be used to increase or decrease theoverall sign height to an even 50mm increment.However, any reduction shall be limited to 90%of the original spacing.Changes made to achieve the recommended heightand width shall be spread as evenly as possibleover the appropriate adjustable
dimensions. If thepreliminary sign height or width is a halfwaybetween two recommended sign heights or widths,always round to the higher size.Center the smaller lettering with the center of thewider lettering.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-11Proportion:24 cm= 4.85 cmFirst letter:page 6; connected on left:55 mm x 4.8=26.40 cmSecond letter:Page 3; connected on right10 mm x 4.8=4.80 cmSpace:from Table A, 1-1/2 squares:7.5 mm x 4.8=3.60 cmThird letter:page 5; unconnected:30 mm x 4.8=14.40 cmSpace:from Table A, overlap by 1-1/2 squares:7.5 mm x 4.8=-3.60 cmFourth letter:page 9; end of word:53 mm x 4.8=25.44 cmSpace between words:6 squares:30mm x 4.8=14.40 cmFirst letter:page 3; unconnected:8 mm x 4.8=3.84 cmSpace:from Table A, 1-1/2 squares:7.5 mm x 4.8=3.60 cmSecond letter:page 11; connected on left:22 mm x 4.8=10.56 cmThird letter:page 10; connected both sides:50mm x 4.8=24.00 cmFourth letter:page 12; connected on right:45mm x 4.8=21.60 cmSpace:from Table A, no space:=0.00 cmFifth letter:page 5, unconnected:30mm x 4.8=14.40 cmSpace:from Table A, overlap by 2 squares:-10 mm x 4.8=-4.80 cmsixth letter:page 11, connected on left:22 mm x 4.8=10.56 cmSeventh letter:page 12, connected both sides:27 mm x 4.8=12.96 cmEighth letter:page 6, end of word:80 mm x 4.8=38.40 cmTotal Length of Message=220.56 cm Example 900-01Sample Calculation Of Arabic Message Width
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-12904.06.02Multiple Message Guide Signs(Example 900-03)For multiple message guide signs, the rules andbase dimensions for a single message guide shallapply, with a few additions and exceptions.Guide sign width shall be determined by thewidest message (message width, arrow width andoffsets), measured as if it was a single messageguide sign.To achieve a recommended height, changes in headjustable dimensions should be spread as evenlyas possible throughout all messages.The multiple sign should be shown with a similardimensional breakdown as the single message sign(Example 900-02).The following paragraphs provide guides for usewith messages containing arrows. Separate guidearrows for each message:• The smaller message shall not be centeredwith the larger message, but placed with thesame offsets from the guide arrow side of thesign as if they were a single message sign.• A single white stripe of 3 cm or 5 cm shall beplaced between all messages that use separateguide arrows. English and Arabic letteringshall be offset from this line as from theborder stripes in a single message guide sign.• It is preferable to place the guide arrows onopposite sides of the guide sign.Separate guide arrows for each message:• These multiple messages shall be centeredwith the center of the largest message.• The dimension between two messages shall bethe same as between the Arabic lettering andthe upper border stripe on a single messageguide sign.• The guide arrow shall be vertically centered.It will also be horizontally offset from thelargest message as in a single message sign.Separate guide arrows for each message (multiplemessages):• The smaller messages shall not be centeredwith largest message, but placed with thesame offsets from the guide arrow side of thesign as if they were a single message sign.• A single white stripe of 3 or 5 cm shall beplaced between all messages that use separateguide arrows. English and Arabic letteringshall be offset from this line as from theborder stripes in a single message guide sign.
• It is preferable to place the guide arrows onopposite sides of the guide sign.Same guide arrow for multiple messages:• These multiple messages shall be centeredwith the center of the largest message.• The dimension between two messages shall bethe same as between the Arabic lettering andthe upper border stripe on a single messageguide sign.• The guide arrow shall be vertically centered.It will also be horizontally offset from thelargest message as in a single message sign.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-13Dimensions For Guide SignsAleph Height24 cm30 cmA35B*2027C2027D(See Note A)E2430F*2430G*35(See Note B)40H*30(See Note B)40J(See Note C)K(See Note D)(A) 10 cm + largest distance an Arabic letter in the message goes below the baseline. (B) From the edge of the wider message, Arabic or English.(C) See Standard Drawings for arrow dimensions.(D) (Height of sign - arrow height) 2, use whole numbers.* These dimensions may be adjusted to comply with recommended heights and widths. Example 900-02Dimensions For Guide Signs
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-14 Example 900-03Multiple Message Guide Signs
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-15904.07STANDARD ARABIC SCRIPTFOR HIGHWAY SIGNSThis section consists of pages numbered 1through 14 of 14. The design of each letter andnumber is shown on a 5 mm grid in Figures900.06 through 900.17. Letter shapes are shownwhen the letter occurs at the end of a word (or isunconnected), at the beginning of a word, and inthe middle of a word (generally shown left to rightrespectively). The length of the connections toproceeding and following letters are included inthe design. However, they may be increasedslightly to maintain proper proportion with theEnglish legend if it is larger than the Arabiclegend.Letter height and spacing between words shall bedetailed in the project drawings.Certain Arabic letters are not connected withletters which follow in the same word. The spacebetween the letters and the letters which followthem are given in Figure 900.05. 1 of 14
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-206 of 14Figure 900.09Guide Sign Lettering
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-217 of 14Figure 900.10Guide Sign Lettering
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-228 of 14Figure 900.11Guide Sign Lettering
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-239 of 14Figure 900.12Guide Sign Lettering
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-2410 of 14Figure 900.13Guide Sign Lettering
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-2511 of 14Figure 900.14Guide Sign Lettering
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-2612 of 14Figure 900.15Guide Sign Lettering
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-2713 of 14Figure 900.16 Guide Sign Lettering
ROADWAY DESIGN MANUAL – Roads and BridgesPart 2900-2814 of 14Figure 900.17 Guide Sign Lettering
ROADWAY DESIGN MANUAL – Roads and BridgesPart 21100-1SECTION 1100ROADSIDE DEVELOPMENT1101LANDSCAPINGLandscaping and the associated irrigation systemfor the roadside areas and medians will bedesigned by the Agricultural Section of the AbuDhabi Municipality. The Design ProjectManager is responsible for coordinating with theAgricultural Section to ensure that they are awareof the Project and its design schedule.Special permission from the Municipality isrequired for the removal of any green (planted)area. Newly created areas suitable for plantingalong with remaining green areas must beidentified and presented on the General Plans.The Design Project Manager must provide theseplans to the Agricultural Section so that they candesign the new landscaping and irrigation system.Close coordination with the Agricultural Sectionis essential to ensure that the irrigation design iscompleted early enough to be incorporated intothe Tender Documents of the roadway project.Agricultural planting areas should be shown onthe general plans designated as green areas.Green areas within the residential sectors, (sectorspredominantly villas or low rise structures),should be maximized while reducing paved areas.In general the green areas should be limited to thefront portion of building plots. The areasbetween and behind the existing buildings shouldbe paved with pedestrian or vehicular pavers asapplicable. However, each sector must beconsidered individually. Local residents,Mosques, Embassies and/or some othersignificant feature within the sector, often requirespecial (non-standard) treatment.1102IRRIGATIONIt may be required to design an irrigationreservoir with electrical and water services. Ingeneral, it will include the reservoir, pump-housestructure and the incoming services, but will notinclude the interior piping, wiring or pumpingsystems.The Agricultural Section will determine if areservoir is required on a project. They will, alsodetermine its location and size. However, finalapproval for including this work in a project mustcome from the Road Section.1102.01IRRIGATION DUCTSAll irrigation facility crossings of all roadwaysshall be accommodated within a duct. Ductdetails are included on the Miscellaneous UtilityDetail Standard Drawings. Duct crossings shouldbe located within allocated service reservationcorridors.Guidelines for providing the irrigation ducts andappurtenances are:1. Ducts for irrigation lines may be GlassReinforced Plastic (GRP) orPolyvinylchloride (PVC) pipe conforming tothe Standard Specifications. 2. Generally, ducts will be provided under theroadway at intersection crossings. Additionalcontingency ducts shall be located at spacingof approximately 250 to 300 meters betweeninterchanges. Specific contingency ductrequirements for each project must becoordinated with the Agriculture Department.Ducts under the roadway pavement must bealigned with each other in the median, bothhorizontally and vertically.
3. Ducts should normally have one meter of cover, however, one-half meter of cover isacceptable where positioning is due toconflicts with existing or proposed utilities.In superelevated sections, the ducts shouldhave approximately the same degree of crossslope as the highway. All ducts should havea nominal (1%±) slope for drainage. 4. The end of ducts must extend 0.5 meters(minimum) past back face of curbs orsidewalks when in curbed situations. 5. The end of the ducts should extend into theverge area in an un-curbed condition. Theintent is to maintain the cover from the
ROADWAY DESIGN MANUAL – Roads and BridgesPart 21100-2sideslope at one meter (minimum) where theirrigation line comes out of sleeve. 6. Ducts should be considered wheremaintenance roads and driveways crossirrigation lines.1103FENCINGThe Designer and Abu Dhabi Road Section shallreview fence requirements on a project specificbasis.1104SLOPE PAVINGSlope paving at bridge abutments shall conformto the Abu Dhabi Road Section Standard slopepaving details.Where the mainline is depressed below the localcrossroad, the slope paving shall approximate thetypical cross section contours. A 6 meter gradingtransition at each edge of the slope paving shouldbe indicated on the plans.Special treatment of slope paving may beapplicable at specific locations. The Designershould coordinate slope paving treatments withthe Abu Dhabi Road Section.1105SWEET SAND COVERINGIn general, all proposed green areas shall becovered with a 30 cm minimum depth of sweetsand at the finish grade.The Designer shall calculate the quantity of sweetsand required for the project. The General Plandrawings will show the green areas included in theproject.1106STREET FURNITURE1106.01GENERALStreet furniture to be provided as part of the AbuDhabi Roadway Section projects includesbenches, bus shelters, telephone booths andsidewalk lighting. The purpose is to providepedestrian amenities and to enhance the urbanenvironment with street furniture that has auniform and visually pleasing design andappearance.In general, street furniture will only be providedin roadway projects at the direction of the RoadSection. For urban interchange projects,installation of street furniture will be included aspart of the proposed improvements. On ruralinterchange contracts, the extent of streetfurniture required could range from pedestriansignals to a full compliment of street furnitureelements. On all types of projects, during theclose of the Concept Phase, the Designer shouldconsult with the Abu Dhabi Road Section todetermine the types of street furniture that shouldbe provided.Descriptions of the basic function, elements,design standards and procedure for each streetfurniture item are included in following sections.1106.02DESIGNDetails of street furniture have been designed andshown on the Standard Street Furniture Detaildrawings and in the Standard Specifications.These details do not have to be revised from onecontract to the other unless there is a project-specific requirement.1106.03BENCHESBenches provide resting facilities for pedestrians,much needed in Abu Dhabi in view of the warmclimate. There are three types of benchesdesigned for the Abu Dhabi Roadway Sectionprojects, Type A, Type B and Type C.1106.03.01Type A bench
This type of bench is comprised of two precastconcrete ends and wood slats (over aluminumtubes), and does not have a backrest. The Type Abench is always used in combination with theType B bench, except when it is used at taxistops.1106.03.02Type B benchThis type of bench includes a back rest, a planterand a waste receptacle. Basic elements of thebench itself are the same as the Type A bench,
ROADWAY DESIGN MANUAL – Roads and BridgesPart 21100-3except for the back rest and higher ends. TheType B bench is also used in combination with aType A bench to create a small gathering placefor a group of people.1106.03.03Type C benchThis type of bench is comprised of the sameelements as a Type A bench except it is used onlyin bus shelters.Subject to space availability, basic criteria forplacement of benches are as follows:1. Two combination Type A/Type B benchesare placed at every intersection, with each indifferent quadrant (preferably diagonalquadrants).2. If space does not permit the abovearrangement, a Type B bench is placed in thesame fashion.3. At least two Type B benches are placed ateach side of the main road between twointersections.4. Two Type C benches are placed within eachbus shelter (considered as part of and paidunder bus shelters).5. One Type A bench is placed at each taxi stop.1106.04BUS SHELTERSBus shelters are placed on bus stop sidewalks toprovide shade and seating for bus passengers.Bus shelters are to be placed at every bus stopexcept where space limitations prohibit their use.They are to be located at the far (downstream,according to the direction of traffic) end of thebus stop with one meter from the edge of thecurb.1106.05TELEPHONE BOOTHSFoundations for telephone booths will be providedin road projects, the telephone booth andoperating equipment are the responsibility of Etisalat.Etisalat determines locations and quantity of telephone booths to be included in each Contractas approved by the Road Section.1107NOISE ABATEMENTThe Designer and the Abu Dhabi Road Sectionshall review any noise abatement requirements ona project specific basis. In general, the Designeris to mitigate, as much as possible, any increasein the traffic noise, especially in residentialneighborhoods.In special circumstances involving sensitive areas,depressed roadways or noise abatement walls maybe required.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 100-1PART 3STRUCTURE DESIGNSECTION 100DESIGN CRITERIA101GENERAL101.01PURPOSEThe purpose of this section is to provide BridgeDesign Criteria in order to establish a uniformproject design and construction policy that willaid the Consultant in the preparation of finaldesign, plans and specifications, and insure safeand uniform structural capacity throughout theproject.Structures shall be designed in accordance withthe latest edition, including revisions, of theStandard Specifications for Highway Bridges -published by the American Association of StateHighway and Transportation Officials(AASHTO) and the Structural Design Standardsincluded herewith in Part 3 of this RoadwayDesign Manual. The design shall be based on thelatest edition of the AASHTO specifications asexisting on the date of the design contract. TheStructural Design Standards presented hereundershall govern over the AASHTO Specificationswherever the are “At Variance With” or “InAddition To” the AASHTO Specifications.These criteria set forth minimum standards. TheConsultant may propose more conservativecriteria if, in his judgment, such criteria arerequired. However, all deviations from thecriteria must be justified and receive priorapproval from the Abu Dhabi Roads SectionProject Manager.101.02DEFINITIONSThe following definitions and abbreviations areprovided to clarify usage of terms and to avoidthe need for excessive verbiage.AASHTO—American Association of StateHighway and Transportation Officials StandardSpecifications for Highway Bridges, 15th Edition-1992, including all Interim Specifications todate.Approval—Approval as obtained from the AbuDhabi Roads Section Project Manager.Drainage Report—The Drainage Report asproduced by the Bridge Drainage Section or,when applicable, by a consultant.Geotechnical Report—The Geotechnical Reportincluding the Foundation Design Report asproduced by the Geotechnical Section or by aconsultant.Special Provisions—The Special Provisions tothe Standard Project Specifications as specificallywritten for each individual project.Standard Specifications—The Standard ProjectSpecificationsAASHTO Specifications for StructuralSupports—The AASHTO StandardSpecifications for Structural Supports forHighway Signs, Luminaries and Traffic Signals,latest Edition.101.03BRIDGE TYPESBridge Definition—
“A ‘Bridge’ is defined as astructure including supports erected over adepression or an obstruction, as water, highwayor railway and having a track or passageway forcarrying traffic or other moving loads and havingan opening measured along the center of theroadway of more than 6.00 meters betweenundercopings of abutments or springlines of arches or extreme ends of openings for multipleboxes; it may include multiple pipes, where theclear distance between openings is less than half of the smaller contiguous opening.”Bridge—The term “bridge” is usually reservedfor structures over water courses or canyons.Overpass—A structure carrying the principalroute over a highway street or railroad.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 100-2Underpass—A structure which provided forpassage of the principal route under a highway,street, railroad or other feature.Traffic Interchange—An overpass or underpassis also called a T.I. if on and off ramps areprovided to the intersecting roadway.Viaduct—A structure of some length carrying aroadway over various features such as streets,waterways or railroads.Tunnel—A structure carrying a roadway througha hill or mountain.Pedestrian Overpass—A structure carrying apedestrian walkway over a roadway.Pedestrian Underpass—A structure whichprovides for passage of a pedestrian walkwayunder a roadway.102DESIGN FEATURES102.01GENERALThe general features of design shall be asspecified in Section 2 of AASHTO except asclarified or modified in this manual.102.02DESIGN METHODSALL BRIDGE MEMBERS ARE TO BEDESIGNED IN ACCORDANCE WITHAASHTO AND THE REQUIREMENTS OFTHIS MANUAL. (Other standards may beallowed with Department approval.)102.03VERTICAL CLEARANCE ATSTRUCTURES(AASHTO 2.2.3)The following are minimum vertical clearancestandards for highway traffic structures,pedestrian overpasses, railroad overpasses,tunnels and sign structures. Lesser clearancesmay be used only under very restrictiveconditions, upon individual analysis and with theapproval of the Abu Dhabi Roads Section ProjectManager.102.03.01Highway Traffic StructuresThe design vertical clearance to structurespassing over Freeways, Highways and all Ruraland Urban Arterials shall be at least 6.00 metersover the entire roadway width, including auxiliarylanes and shoulders. An allowance of 150millimeters is included to accommodate futureresurfacing. This allowance may be waived if theroadway under the structure is surfaced withportland cement concrete.The design vertical clearance to structurespassing over all other highways and streets shallbe at least 5.50 meters over the entire roadwaywidth, including auxiliary lanes and shoulders.An allowance of 150 millimeters is included toaccommodate future resurfacing. This allowancemay be waived if the roadway under the structureis surfaced with portland cement concrete.Certain routes have been designated as truck routes. On these routes, larger vertical clearancemust be maintained. For future projects, theseroutes will be identified by the Abu Dhabi RoadsSection Project Manager during the conceptstage.102.03.02Pedestrian Overpasses
Because of their lesser resistance to impacts, theminimum design vertical clearance to pedestrianoverpasses shall be 6.00 meters regardless of thehighway system classification. An allowance of 150 millimeters is included to accommodatefuture resurfacing.102.03.03Railroad OverpassesStructures over railways shall provide a minimumclearance of 7.00 meters above top of rail, exceptthat overhead clearance greater than 7.00 metersmay be approved when justified on the basis of railroad electrification. No additional allowanceshall be provided for future track adjustments.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 100-3102.03.04TunnelsThe minimum design vertical clearance fortunnels shall be at least 6.00 meters for freewaysand arterials and at least 5.50 meters for all otherhighways and streets.102.03.05Sign StructuresBecause of their lesser resistance to impacts, theminimum design vertical clearance to signstructures shall be 6.00 meters regardless of thehighway system classification. An allowance of 150 millimeters is included to accommodatefuture resurfacing.102.03.06Width (AASHTO 2.3.1)The horizontal clear width for rural bridges whereapproach guardrail is used shall provide anadditional width on each side of the approachroadway width to allow the bridge rail to line upwith the approach guardrail. The horizontal clearwidth for urban bridges, in which curb and gutterand/or sidewalks are used, shall equal theapproach roadway width.102.04RAILINGS (AASHTO 2.7)In general, concrete barrier should be used as avehicular railing. For situations requiring adifferent barrier type, only FHWA crash testapproved bridge rails are allowable alternatives.Bridge rails shall be constructed vertical.Concrete barriers shall not be slipformed. Forcast-in-place, post-tensioned concrete bridges,barriers shall be cast after post-tensioning andmay be cast before falsework removal.102.05CONCRETE BARRIERTRANSITIONSTransitions from bridge concrete barrier toapproach guardrail should, when practical, belocated on the bridge, approach slab orwingwalls.102.06APPROACH SLABSConcrete approach slabs shall be used on allstructures. Approach slabs serve a dual purposeof providing a transition structure from the bridgeto the approach roadway should the roadwayembankment settle and of eliminating the live loadsurcharge of the abutment backwall when theconditions specified in AASHTO 3.20.4 aresatisfied. Approach slabs are to be designedusing the Service Load Design Method and shallcover the entire roadway width including theshoulders, from wingwall to wingwall.102.07ANCHOR SLABSWhen approach roadways are paved withportland cement concrete pavement (PCCP),adequate means shall be provided to preventpavement growth from causing damage to thebridge. Use of a properly designed anchor slab isone means of providing such protection102.08DECK DRAINAGEOn grade separation structures, roadway drainsshall not discharge water onto unprotectedembankment slopes or within five meters of thetraveled roadway below, nor shall drains belocated less than 1.5 meters from the centerlinesof abutments or piers. In urban areas collectionof deck drainage in a pipe system may berequired, with down drains in or on pier columnsdischarging into storm drainage collector systems.Consideration should always be given to providecollector drains and discharge systems on theapproach roadway gutter rather than on thebridge.For bridges with sidewalks, expansion joints shallbe turned up at the curb line to prevent roadwaywater from entering sidewalk areas. Appropriatemeans shall be taken to ensure that sidewalk drainage does not pond and that the water doesnot escape around the wing walls
and erode theembankment.For deck drainage design criteria, refer to theROADWAY DESIGN MANUAL - Drainage.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 100-4102.09WING WALLSWing walls shall extend 1.50 meters beyond thecatch point, where catch point is defined as theintersection of the fill slope in front of theabutment with the finished approach grade at theoutside face of the wing wall. The bottom of thewing walls shall be embedded a minimum of 1meter into the approach fill at the end of the wingwalls.102.10LIGHTINGConsideration shall be given to special lightingabove and below the structure. This lighting shallserve as ornamental lighting to enhance theaesthetics and also to enhance safety. Thislighting is in additional to the normal roadwaylighting. Refer to the lighting section of thismanual for roadway lighting criteria.Coordination of all structure lighting with existingand/or planned lighting of connecting andadjacent roads must be considered.102.11BRIDGE DECK ELEVATIONSThe project design group shall prepare eithercomputer plotted contours at 0.1 meter intervalsat a 1:50 scale or tabulate elevations at 3.0 meterintervals along the profile grade line, withadditional elevation points on each perpendicular(radial) such that the bridge can be completelycovered with 0.1 meter contours. The number of elevation points on each perpendicular must besuch that the lowest, or the highest, point isoutside the bridge for use by the constructionsupervision staff to help check the contractor’sgeometric layout.102.12CONCRETE CRACK CONTROLMaximum flexural crack width at the tensile faceof a reinforced concrete section shall not exceed0.25mm for normal conditions of exposure and0.20mm for marine and unfavorable conditions of exposure (such as alternate wetting and drying,humid atmosphere, direct contact with soil, etc.).The allowable crack width can be increased by25% under earthquake/wind/temporaryconstruction conditions.102.13CORROSION PROTECTION(AASHTO 8.22)Due to the adverse corrosive environment, allreinforced concrete structures shall use epoxycoated rebar unless otherwise directed by theProject Manager.103ARCHITECTURALCONSIDERATIONS103.01PROCEDUREFollowing the approval of the civil and basicstructural concepts for an interchange, includingconfiguration, alignment, profile and pierlocations, the Project Design Manager will meetwith the Structural, Architectural, and GraphicsDesign Managers to develop basic alternativesand set architectural design parameters.Environmental constraints and influences will beestablished. The Concept Design Team willdetermine the number of structural concepts andarchitectural options to be studied. The purposeof these studies will be do develop applicableconcepts and options in the form of presentationdisplays, to be used as a basis for the Abu DhabiRoads Section review and decision making. Theapproved displays are submitted to the AbuDhabi Roads Section for review and selection of the desired alternative. The approved scheme thewill progress to the preliminary and final designphases.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 100-5103.02GENERAL CRITERIAEvery effort should be made in the treatment of structures to respect the Islamic design andculture.Design concepts should be easily implemented.Construction considerations are also taken intoaccount in the architectural treatment concepts.Architectural elements should be functional,durable and easily maintained.Each structure should have individuality;however, a totally different design is not requiredfor each structure. It is desirable to maintain asense of continuity throughout the wholeprogram.Architectural treatment should be continuousthrough an interchange.In the downtown area, underpasses spanning agiven roadway should have similar treatment toestablish continuity. Decorative and medianlighting should be similar on overpasses along agiven route.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 200-1SECTION 200DESIGN LOADS201LOAD TYPES201.01GENERALLoads shall be as specified in Section 3 of AASHTO except as clarified or modified in thismanual.201.02DEAD LOADS (AASHTO 3.3.1)Utility loads shall be included as applicable.201.03FUTURE WEARING SURFACE(AASHTO 3.3.3)All new structures shall be designed to carry anadditional dead load of 120 kg/m2from curb tocurb of roadway to allow for a future wearingsurface. This load is in addition to any wearingsurface which may be applied at the time of construction. The weight of the future wearingsurface shall be excluded from the dead load fordeflection calculations.201.04WEARING SURFACE(AASHTO 3.3.5)The top 15 millimeters of the deck shall beconsidered as a wearing surface. The weight of the wearing surface shall be included in the deadload but the 15 millimeter shall not be included inthe depth of the structural section for all strengthcalculations including the deck, superstructureand the pier cap, where appropriate.201.05HIGHWAY LOADS(AASHTO 3.7.1.1)P Loads (permit design live loads) are specialvehicular loads that will be applied only tospecific structures, such as interchange ramps,and at the direction of the Abu Dhabi RoadsSection.201.06 STRUCTURE LOADINGS1. Highway Bridge Live Load: AASHTO 20-44increased by 25 percent.2. Wind Velocity: 160 kilometers per hour.3. Humidity Range: 25 percent to 100 percent.4. Earth Pressure: For specific projectrecommendations, refer to Soils Report5. Future Utilities: 75 kg/m² of Bridge Deck.6. Earth Weight: 1920 kg/m37.
Earthquake Loading: Only to be consideredif directed by the Road Section ProjectManager.201.07FRICTION FORCES(AASHTO 3.9.2)Friction forces due to elastomeric bearing pads orTFE surfaces shall be based on theManufacturer’s data for the bearing used.201.08THERMAL FORCES(AASHTO 3.16)1. Temperature Range: 70ºC.2. Temperature Fall: 30ºC to 0ºC = 30ºC.3. Temperature Rise: 30ºC to 70ºC = 40ºC.4. The temperature gradient between the topslab and bottom slab of concrete box girderbridges is 20ºC.201.09STREAM FORCES(AASHTO 3.18.1)A Drainage Report shall be produced by BridgeDrainage Section or a consultant, whenappropriate, for all stream and/or channelcrossings. The designer should review theDrainage Report for a full understanding of waterway considerations. The report shouldcontain as a minimum, the following informationfor both the critical flow and superfloodconditions: • High water elevation• Mean Velocity• Scour Elevations (General and Local)• Angle of attack • Required bank protection• Special drainage considerations•
Horizontal and Vertical Clearances
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 200-2• Direction of FlowFor design for the most critical flow and thesuperflood condition, the following criteria shallbe used unless more severe criteria isrecommended in the Drainage Report.Design calculations of stream forces on piers overnatural water courses shall assume a 0.6 meterincrease in pier width per side due to blockage bydebris with a shape factor k = 1.40 for the first3.5 meters of depth. For flows with depthsgreater than 3.5 meters, only the top 3.5 metersshall be assumed blocked by debris with lowersections using the actual pier width and a shapefactor in accordance with AASHTO. Foruncased drilled shafts, a 20% increase in diametershould be assumed to account for possibleoversizing of the hole and any irregular shape.The force distribution on the pier shall beassumed to vary linearly from the value at thewater surface to zero at the bottom of the scourhole as described in AASHTO.When the clear distance between columns orshafts is 5.00 meters or greater, each column orshaft shall be treated as an independent unit forstream forces and debris. When the clear distanceis less than 5.00 meters the greater of the twofollowing criteria shall be used: 1) Each columnor shaft acting as an independent unit or 2) Allcolumns or shafts acting as one totally cloggedunit with 0.6 meters of debris normal to the flowadded on each end.The average main channel velocity for theappropriate flow condition shall be used incalculating the stream forces. The water surfaceelevation shall be the high water elevation for theappropriate flow condition. A minimum angle of attack of 15 degrees shall be assumed.Scour may be categorized into two main types:general and local. General scour is the permanentloss of soil due to degradation or mining whilelocal scour is the temporary loss of soil during apeak flow. Local scour may consist of two types:contraction scour and local pier or abutmentscour. Contraction scour occurs uniformly acrossthe bridge in the stream width. Local pier andabutment scour occurs locally at substructureunits due to the turbulence caused by the presenceof the substructure unit.Bridges over natural water courses shall beinvestigated for four different streambed groundlines. Refer to Figure 200.01 for an illustrationof these cases.Case 1represents the “as-constructed” streamcross section. For this case, the bridge shall bedesigned to withstand the forces from theAASHTO Groups I to VII load combinations.Case 2represents the long term dry streambedcross section, i.e. the “as-constructed” streamcross section minus the depth of the generalscour. For this case, the bridge shall be designedto withstand the same forces as for Case 1. Therequirements contained in AASHTO 4.4.5.2 neednot be met.Case 3represents the streambed cross sectioncondition for the most critical design flow.Abutment protection is designed to withstand thisevent and abutments may be assumed to beprotected from scour for this condition. Piers willexperience the full general and critical flow localscour. For this case, the bridge shall be designedto withstand the forces from the AASHTOGroups I to VI load combinations.
Case 4represents the streambed cross sectionconditions for the superflood condition. For thiscase, all bank protection and approachembankments are assumed to have failed.Abutments and piers should be designed for thesuperflood scour assuming all substructure unitshave experienced the maximum scoursimultaneously. For this case, the bridge shall bedesigned to withstand the following forces: DL +SF + B + 0.5W. For members designed using theWSD Method an allowable overstress of 140%shall be used. For members designed using theLFD Method a gamma factor of 1.25 shall beused.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 200-3Figure 200.01Groundline Variations Due to Scour201.10LATERAL EARTH PRESSURE(AASHTO 3.20.1)For backfills compacted in conformance with theStandard Specifications, active pressure forunrestrained walls should be calculated using aninternal angle of friction of 33 degrees unlessrecommended otherwise in the GeotechnicalReport.201.11DIFFERENTIAL SETTLEMENT(AASHTO 3.3.2.1)Differential settlement shall be considered in thedesign when indicated in the Geotechnical Report.The Geotechnical Report should provide themagnitude of differential settlement to be used inthe design. If not addressed in the GeotechnicalReport, and at the direction of theRoads Section Project Manager, a minimumdifferential settlement of 25mm may be used inthe design.Differential settlement, if required, shall beconsidered the same as temperature and shrinkageforces and included in Group IV, V and VI loadcombinations.201.12EARTHQUAKES(AASHTO 3.21)Earthquake criteria will only be considered in thedesign process at the direction of the RoadSection Project Manager. If so directed, referenceis made to AASHTO Division 1-A.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 200-4202DISTRIBUTION OF LOADSLoads shall be distributed as specified in Section3 of AASHTO except as clarified or modified inthis manual.202.01SUPERIMPOSED DEADLOADDISTRIBUTION(AASHTO 3.23.2.3.1.1)The weight of curbs, barriers and sidewalks foran I-Girder bridge with composite concrete deck shall be distributed as follows:i) Equally over all girdersii) Equally over all girders under the sidewalk iii) If there is no sidewalk, curb and barrier shallbe distributed 60% to the exterior girders and40% to the interior girders.Each girder shall be designed for the conditionthat causes highest stresses. Girders shall in noway be designed for loads less than that specifiedin AASHTO Section 3.202.02CONCRETE BOX GIRDERS(AASHTO 3.23.2.3.2.2)In calculating the number of lanes of live load onthe superstructure, the entire cross section of thesuperstructure shall be considered as one unitwith the number of lanes of live load equal to theout-to-out width of the deck in meters divided by4.27. Do not reduce this number for multiplelanes as specified in AASHTO 3.12.1 nor roundto a whole number as specified in AASHTO3.6.3.202.03PRESTRESSED VOIDED SLABS(AASHTO 3.23.4.3)The equations for distribution of live loadcontained in the Fifteenth Edition (1992)including the 1993 and 1994 Interims shall not beused. The new distribution factors in the latestedition, initially changed in the Fourteenth Edition(1989), are based on tests on T-beams and are notdeemed appropriate for voided slabs or boxbeams. Instead, the equations in the ThirteenthEdition (1983) as repeated below shall be used todistribute live loads:In calculating bending moments in multi-beamprecast concrete bridges, conventional orprestressed, no longitudinal distribution of wheelload shall be assumed.The live load bending moment for each sectionshall be determined by applying to the beam thefraction of a wheel load (both front and rear)determined by the following relations:Load Fraction = SDWhereS = 12 NL + 9NgD = 5 + NL + ( 3- 2NL ) ( 1-C )2when C<310 7 3D = 5 + NL when C>310NL = total number of traffic lanes fromAASHTO Article 3.6Ng=number of longitudinal beamsC = K(W/L), a stiffness parameterW = overall width of bridge in metersL = span length in metersValues of K To Be Used in C = K(W/L)
Bridge TypeBeam Type K Multi-BeamNon-Voided Rect 0.7Rect. w/ Circular Voids 0.8Box Section 1.0Channel 2.2202.04PRESTRESSED BOX BEAMS(AASHTO 3.23.4.3)The equations for distribution of live loadcontained in the Fifteenth Edition (1992)including the 1993 and 1994 Interims, shall notbe used. Refer to Distribution of Loads inSection 202.02 of this manual for criteria ondistribution of loads.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 200-5202.05LATERAL TENSIONING OFMULTI-BEAM UNITS(AASHTO 3.23.4.1)Each lateral tensioning tie shall consist of a 38millimeter diameter mild steel bar tensioned to13,560 kg. Tension in the 38 millimeter diametermild steel should be applied by the turn of nutmethod. The designer should determine thenumber of turns of the nut required to achieve the13,560 kg force. This value should be shown onthe plans.A36M steel bars for the tie normally come in 6meter lengths. the final total length of the tieshould be made using threaded couplers; notwelded splices. When couplers are used, the holethrough the diagram should be increased from thenormal 64 millimeter to 102 millimeter diameterto accommodate the couplers.Adequate means shall be used to ensure that theties are adequately protected from corrosion. therod, nut and bearing plate shall be galvanized inaccordance with ASTM A153 (AASHTO M-232).202.06LIVE LOAD DISTRIBUTION(AASHTO 3.6.3 AND 3.12.1)In designing the superstructure, the live loaddistribution factors shall not be reduced formultiple lanes as specified in AASHTO 3.12.1 orrounded to a whole number as specified inAASHTO 3.6.3. These two reductions apply tosubstructure design only.203LOAD FACTORSAn essential feature of Load Factor Design (LFD)requires raw design loads or related internalmoments and forces to be modified by specifiedload factors (γ , gamma andβ, beta), andcomputed material strengths to be reduced byspecified reduction factor (φ, phi).These are safety factors which ensure certainmargins for variation. The three different kindsof factors are each set up for a distinct purpose,each independent of the other two. In this way,any one of them may be refined in the futurewithout disturbing the other two.1.γ (Gamma) FactorTheγ (gamma) factor is the most basic of thethree. It varies in magnitude from one loadcombination to another, but it always applies toall the loads in a combination. Its main effect isstress control that says we do not want to usemore than about 0.8 of the ultimate capacity. Itsmost common magnitude, 1.3 lets us use 77%.Earthquake loads are not factored above 1.0because we recognize that stresses in the plasticrange are allowed, as long as collapse does notoccur.An example may be given to justify the use of gamma of 1.3 for dead load. Assuming the liveload being absent, the probable upper value of thedead load could be a minimum of 30% greaterthan calculated. For a simple structure thispercentage may be as follows:10%due to excess weight.5%due to misplaced
rebar5%structure behavior approximation10%stress increase (actual vs. calcs.)30%Total variation assumed to occurconcurrently at the section mostheavily stressed.2.β(Beta) FactorThe second factor,β(beta), is a measure of theaccuracy with which we can predict various kindsof loads. It also reflects the probability of oneload’s simultaneous application with others in acombination. It applies separately, with differentmagnitudes, to different loads in a combination.For example, it is usually 1.0 for dead load. Itvaries from 1.0 to 1.67 for live loads and impact.Due regard has been given to sign in assigningvalues to beta factors, as one type of loading mayproduce effects of opposite sense to that producedby another type. The load combinations withβD=0.75 are specifically included for the casewhere a higher dead load reduces the effects of other loads.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 200-6The beta factors for prestressing force effects areset so that when multiplied by the respectivegamma factor, the product is unity. Beta of 1.67for live load plus impact from H loads reflectsAASHTO’s way of handling permit loads.3.φ(Phi) Factorφ(phi), the third factor, relates to materials and iscalled either a capacity reduction factor or astrength reduction factor. Its purpose is toaccount for small adverse variations in materialstrength, workmanship, and dimensions. Itapplies separately to different magnitudes forvarious load effects in reinforced concrete, andvarious manufacturing processes in prestressedconcrete. Sinceφrelates to materials rather thanloads, its values are given in the various materialspecifications. For structural steel it is almostalways 1.0. For concrete it varies from 0.7 to1.0.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 300-1SECTION 300REINFORCED CONCRETE301GENERALReinforced concrete design criteria shall be asspecified in Section 8 of AASHTO except asclarified or modified in this manual.301.01CONCRETE (AASHTO 8.2)Concrete for highway structures shall have thefollowing minimum cylinder strengths, unlessotherwise directed by the Project Manager:Decks except barriersf ′c = 280 kg/cm2Abutmentsf ′c = 210 kg/cm2Piers except footingsf ′c = 280 kg/cm2Drilled Shaftsf ′c = 280 kg/cm2All otherf ′c = 210 kg/cm2For Design Load use Concrete Weight = 2500kg/m3• Class K 250 Concrete Design Parametersf ′c = 210 kg/cm2fc = 80 kg/cm2Ec = 220 000 kg/cm2• Class K 335 Concrete Design Parametersf
′c = 280 kg/cm2fc = 110 kg/cm2Ec = 255 000 kg/cm2• Class K 415 Concrete Design Parametersf ′c = 350 kg/cm2fc = 140 kg/cm2Ec = 283 000 kg/cm2301.02DIAPHRAGMS (AASHTO 8.12.3)Reinforced concrete box girder diaphragm criteriashall be the same as for post-tensioned boxgirders as specified under Diaphragms in Section402.06 of this manual.301.03DESIGN METHODS(AASHTO 8.14.1)In accordance with the applicable provisions of AASHTO, the Strength Design Method (LFD)shall be used for the design of all reinforcedconcrete members except where such membersare to be below grade or intended for waterretention, then the Service Load Design Methodshall be used.301.04REINFORCEMENT(AASHTO 8.15.2.2)Concrete shall be reinforced only with fusionbonded epoxy coated reinforcement steelconforming to AASHTO M 31M (ASTMA615M) Grade 400 as follows:• Deformed Round Steel Bar Reinforcement,AASHTO M 31M Grade 400fy = 4 080 kg/cm2fu = 6 120 kg/cm2fs = 1 680 kg/cm2T or C in beamsEs = 2 039 470 kg/cm2• Spiral Reinforcement and Welded WireFabric
Steel Bars used as Spirals, AASHTO M31M Grade 400Steel Wire used as Spirals, AASHTO M32Welded Wire Fabric used as reinforcementin concrete and mortar, AASHTO M 55302SLAB DESIGNSlabs shall be designed in accordance with thecriteria specified in Section 3 of AASHTO exceptas clarified or modified below.All reinforcing bars are to be epoxy coated bars.All reinforcing bars shall be straight bars top andbottom. The use of truss bars will not bepermitted.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 300-2For skews less than or equal to 20 degrees thetransverse bars shall be placed parallel to theskew. For skews greater than 20 degrees thetransverse bars shall be placed normal to thegirders.Use of steel stay-in-place forms should beconsidered during design for steel girder orprecast girder bridges for special conditions only.Some circumstances which warrant suchinvestigation include: bridges over heavilytraveled roads, bridges over live streams andbridges over deep canyons. A discussion on theiruse shall be made in the Design Concept Report.If use of steel stay-in-place forms is notrecommended during design, they will not beallowed during construction due to the extra deadload. Contractor requests for usage duringconstruction will not be approved.302.01SPAN LENGTHS(AASHTO 3.24.1.2)The deck slab span length for AASHTOgirders shall be the clear distance between thetop flanges plus one-half the flange width.302.02SLAB THICKNESS(AASHTO 8.11.1)The thickness of new deck slabs shall bedesigned in 10 millimeter increments with theminimum thickness as shown below, unlessotherwise directed by the Project Manager.Slab Thickness S(m)t(mm)Up to1.800 1901.801 to2.100 2002.101 to2.400 2102.401 to2.700 2202.701 to3.000 2303.001 to3.300 2403.301 to3.600 2503.601 to3.900 260Where S = Design span as defined in AASHTO3.24.1 and above.t = Minimum thickness of deck slab.302.03PROTECTION AGAINSTCORROSION(AASHTO 8.22.1)The minimum clearance for top reinforcing innew decks shall be 50 millimeters with 50millimeter Asphaltic wearing surface and theminimum specified concrete strength (f ′c) shallbe 280 kg/cm2.302.04DISTRIBUTION METHOD(AASHTO 3.24.3)Use the AASHTO method for load distributionon slabs except for unusual loads or unusualstructures such as single cell boxes.302.05RAILING LOADS(AASHTO 3.24.5.2)When barriers are located at the deck edge, thedeck shall be designed to resist both the axialforce and the bending moments due to all deadloads and horizontal rail load or due to all deadloads plus vertical wheel loads, whichever iscritical.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 400-1SECTION 400PRESTRESSED CONCRETE401DESIGN CRITERIA401.01GENERALPrestressed design criteria shall be as specifiedin Section 9 of AASHTO except as clarified ormodified in this manual.Members shall be designed to meet both ServiceLoad Design and Strength Design (Load FactorDesign) criteria as specified in AASHTO.Prestressing steel for precast prestressedmembers and cast-in-place post-tensionedmembers shall be 12.50 millimeter diameter"Uncoated Seven-wire High Tensile ColdDrawn Low Relaxation Strand for PrestressedConcrete" as specified in ASTM A416, Grade270 with f ′c = 18 360 kg/cm2and Eps = 2039 470 kg/cm2. Use of 15.20 millimeterdiameter strand is allowed for cast-in-placepost-tensioned members only.The yield point stress of prestressing steel, f*y,may be assumed equal to 0.90 f ′c for lowrelaxation strand.Prestress losses shall be calculated in accordancewith AASHTO Article 9.16.2.1. The estimatedlosses contained in Table 9.16.2.2 and Article9.16.2.2 shall not be used.Section properties shall be based on gross area of members. Use of the transformed area of bondedreinforcement shall only be used for unusualstructures and only when approved.Web reinforcement for shear shall consist of rebars; not welded wire fabric.The minimum top cover for slab reinforcementspecified in AASHTO Article 9.25.1.2.1 shall be50 millimeters with 50 millimeter Asphalticwearing surface.Expansion and contraction design criteria shall beas specified in Part 3, Section 600 of this manual.401.02ALLOWABLE STRESSES—CONCRETE (AASHTO 9.15.2.2)The maximum allowable tensile stresses in aprecompressed tensile zone at service load afterlosses have occurred shall be in accordance withAASHTO except as modified below:Tension Load Condition AllowableStressGirder DL + Prestress0Total Service Load 0.8ƒ'c401.03SHEAR (AASHTO 9.20)Shear design shall be in accordance withUltimate Strength Design Method contained inthe latest AASHTO Specifications.Prestressed concrete members shall bereinforced for diagonal tension stresses. Shearreinforcement shall be placed perpendicular tothe axis of the member with spacing not-to-exceed three-fourths the depth of the member.The critical sections for shear in simplysupported beams will usually not be near theends of
the span where the shear is a maximum,but at some point away from the ends in aregion of high moment.For the design of web reinforcement in simplysupported members carrying moving loads, it isrecommended that shear be investigated only inthe middle half of the span length. The webreinforcement required at the quarter pointsshould be used throughout the outer quarters of the span if the critical shear section is includedwithin the design section.For continuous bridges whose individual spansconsist of precast prestressed girders, webreinforcement shall be designed for the fulllength of interior spans and for the interiorthree-quarters of the exterior span and based onthe critical shear design section.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 400-2402POST TENSIONED BOXGIRDER BRIDGES402.01GENERALPost-Tensioned Box Girder Bridges shall bedesigned in accordance with AASHTOspecifications. Girders shall be designed byWorking Stress Method and checked by theUltimate Strength Method (Load Factor Design).The deck slab is to be designed by the WorkingStress Method.402.02CONCRETE(AASHTO 9.2 AND 9.22)The following concrete strengths are the desiredstrengths to be used. Higher strengths may beused if approved by the Abu Dhabi Roads SectionProject Manager.Initial f ′c = 290 kg/cm2minimum.Final f ′c = 350 kg/cm2minimumf ′c = 420 kg/cm2maximum402.03BEARING PADSAllow an extra 80mm movement per 100 metersof girder length for long-term creep andshortening due to post-tensioning.402.04CREEP AND SHRINKAGE(AASHTO 9.4)For restrained members in continuous bridgeswhere shortening due to post-tensioning inducesmoments and shears, a shrinkage and creepcoefficient of 1.5 shall be used for design of substructure elements with the total movementequal to 1.5 times the initial shortening. Forsuperstructure elements, no creep factor should beapplied except for long term deflectionconsiderations.402.05FLANGE AND WEBTHICKNESS - BOX GIRDERS(AASHTO 9.9)Minimum top slab thickness shall be 200millimeters. Minimum bottom slab thicknessshall be 150 millimeters. Minimum webthickness shall be 300 millimeters (measurednormal to girder for sloping exterior webs).Interior webs shall be constructed vertical.402.06DIAPHRAGMS (AASHTO 9.10)A single 250 millimeter thick intermediatediaphragm shall be placed at the midspan for allbridges. Special consideration for additionaldiaphragms should be given to box girders withlarge skews, curved boxes and boxes over 2meters in depth. Diaphragms shall be placedparallel to abutments and piers for skews lessthan or equal to 20 degrees and normal to girdersand staggered for skews over 20 degrees.Diaphragms shall be cast integral with girderwebs.402.07DEFLECTIONS (AASHTO 9.11)
The deflection shall be calculated using dead loadincluding barriers, but not the future wearingsurface, gross section properties and calculatedfinal losses. The additional long term deflectionshall be calculated by multiplying the deflectionby two. An additional parabolic shapeddeflection with a peak equal to 30 millimeters per100 meters should be added to the total deflectionfor simple spans. The final long term deflectionshall be the sum of the deflection, the additionallong term deflection and the additional deflectionfor simple spans. The camber shown on the plansshall be the final long term deflection.402.08ALLOWABLE STRESSES -PRESTRESSING STEEL(AASHTO 9.15.1)In calculating the stress in the prestressing steelafter seating, the friction and anchor set lossesonly should be included. For post-tensionedmembers, overstressing for short periods of timeto offset seating and friction losses is permittedbut the maximum allowable jacking stress for lowrelaxation strand shall be limited to 0.78 f ′s.402.09ALLOWABLE STRESSES-CONCRETE (AASHTO 9.15.2)In calculating the temporary stress in the concretebefore losses due to creep and shrinkage, thefriction, anchor set and elastic shortening lossesshould be included.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 400-3Special consideration shall be given to bridgessupported on falsework with large openings wheredeflections could be harmful to the structure.Unless falsework requirements are strengthenedor other means taken to ensure the bridge does notform tension cracks prior to tensioning, themaximum allowable tension in a precompressedtensile zone shall be limited to zero.402.10LOSS OF PRESTRESS(AASHTO 9.16)For multi-span bridges, the cable path shouldhave its low point at the midspan. Design shouldbe based on usage of galvanized rigid ducts withK = 0.00000066 and µ = 0.25. Anchor set lossesshould be based on 16 millimeter set.For creep of concrete, the variable fcds should becalculated using the total dead load applied afterprestressing, including the 120 kg/m2 futurewearing surface.402.11FLEXURAL STRENGTH(AASHTO 9.17)In determining the negative ultimate momentcapacity, the top layer of temperature andshrinkage and bottom layer of distributionreinforcing may be used. In determining thepositive ultimate moment capacity, thelongitudinal flange reinforcing (AASHTO 9.24)may be used.402.12 SHEAR (AASHTO 9.20)Girder webs will be designed for shear using theUltimate Strength Method according to the 1979Interim AASHTO Standard Specifications. Themaximum girder web stirrup spacing will be 300mm within 6 meters from the front face of theabutment diaphragms. This will eliminate theneed for re-spacing the web stirrups at the pointof web flare if the post-tensioning system requiresflaring.The value of "d" to be used in shear calculationsshall be the larger of the calculated "d" value or0.8 times the overall effective depth.Horizontal shear shall be investigated inaccordance with the provisions of AASHTO9.20.4.Calculations shall include the shear due tosecondary moment and cable shear. For curvedbox girder bridges, the shear due to torsion shallbe included.402.13FLANGE REINFORCEMENT(AASHTO 9.24)Reinforcing in the bottom slab of box girdersshall conform to the provisions of AASHTO8.17.2.3 except that the minimum distributedreinforcing in the bottom flanges parallel to thegirders as specified in AASHTO 8.17.2.3.1 shallbe modified to be 0.30 percent of the flange area.402.14METHOD OF ANALYSISThe superstructure may be designed using thesystem as described below:1) The bottom slab, in the vicinity of theintermediate support, may be flared toincrease its thickness at the face of thesupport when the required concrete strengthexceeds 320 kg/cm2. When thickened, thebottom slab thickness should be increased bya minimum of 50 percent. The length of theflare should be at least one-tenth of the spanlength (measured from the center of thesupport) unless design computations indicatethat a longer flare is required.2)
Section properties at the face of the supportshould be used throughout the support; i.e.the solid cap properties should not beincluded in the model.3) Negative moments should be reduced toreflect the effect of the width of the integralsupport.4) Dead load forces should not produce anytension in the extreme fibers of thesuperstructure.5) The superstructure should be designed as aunit with the number of live loads applied inaccordance with Section 202.02 of thismanual.For box girders with severe sloping webs orboxes over 2 meter deep, transverse flangeforces induced by laterally inclined longitudinalpost-tensioning shall be considered in the design.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 400-4Single span structures should be jacked from oneend only. Symmetrical two span structures maybe jacked from one end only or jacked from bothends. Unsymmetrical bridges should be jackedfrom one end or both ends as required by thedesign. Three span or longer structures shouldbe jacked from both ends.Several prestressing systems should be checkedto verify that the eccentricity and anchoragedetails will work. In determining the center of gravity of the strands, the Z factor, the differencebetween the center of gravity of the strands andthe center of the ducts, shall be considered. Forstructures over 120 meters in length, indetermining the c.g. of the strands, the diameterof the ducts should be oversized by 13millimeters to allow for ease of pulling thestrands.For horizontally curved bridges, special careshall be taken in detailing stirrups and duct ties.Friction losses should be based on both verticaland horizontal curvatures. In designing forhorizontal curvature, the exterior web with thesmallest radius shall be used. Consideration tothe ± 5% variation allowed per web shall beincluded.403 PRECAST PRESTRESSEDCONCRETE403.01CONCRETE (AASHTO 9.2)Concrete for highway structures shall have aminimum specified initial and final concretestrengths as shown below. Higher strengthconcrete may only be used when required bydesign and when approved.Initialf ′ci = 290 kg/cm2Minf ′ci = 320 kg/cm2MaxFinalf ′c = 360 kg/cm2Minf ′c = 420 kg/cm2Max403.02DEFLECTIONS (AASHTO 9.11)The Release, Initial and Final Deflections shall beshown on the plans. Deflections shall be shownin centimeters at the tenth points.The Release Deflection equals the deflection theprestress girder undergoes at the time of strandrelease. The Release Deflection includes the deadload of the girder and the release prestressingforce (including the effects of elastic shortening).The Initial Deflection equals the deflection theprestress girder undergoes at the time of erectionprior to the diaphragm or deck pours. The InitialDeflection includes the deflection due to the deadload of the girder, the initial prestressing and theeffects of creep and shrinkage up to the time of erection. The time of
erection should be assumedto be 60 days after release.The Final Deflection equals the deflection due tothe dead load of the deck slab, diaphragms andbarriers and the effects of long term creep on thecomposite girders. The effects of the 120 kg/m2future wearing surface shall be excluded fromdeflection calculations.Minimum build-up at the edge of Type III girdersand smaller shall be 15 millimeters. For Type IV,V and VI girders the minimum build-up shall be25 millimeters. This minimum build-up at thecritical section will ensure that the flange of thegirder will not encroach into the gross depth of the slab.The tops of the erected girders shall be surveyedin the field prior to placement of the deck forming. If the tops of the erected girderelevations are higher than the finish grade pluscamber elevations minus deck slab and buildupthickness, adjustments will have to be made in theroadway profile or in the girder seat elevations.Encroachment into the slab of up to 15millimeters will be allowed for randomoccurrences.403.03ALLOWABLE STRESSES-PRESTRESSING STEEL(AASHTO 9.15.1)For pretensioned members, overstressing theprestressing steel above the initial stressing limitfor short periods of time to offset seating losses isnot permitted.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 400-5403.04ALLOWABLE STRESSES-CONCRETE (AASHTO 9.15.2)In calculating the temporary stress in concretebefore losses due to creep and shrinkage, the steelrelaxation prior to release and the elasticshortening should be included.403.05LOSS OF PRESTRESS(AASHTO 9.16)For creep of concrete, the variable f cds, should becalculated using the total dead load applied afterprestressing including the 120 kg/m2futurewearing surface.For girders with required concrete releasestrengths of 320 kg/cm2or less, the time of release may be assumed to be 18 hours. Forspecified strengths over 320 kg/cm2the time of release should be increased accordingly. Forprecast girders, the final losses shall includerelease losses.The value of relative humidity to be used incalculating shrinkage losses, shall be the value of relative humidity at the bridge site.403.06SHEAR (AASHTO 9.20)The value of "d" to be used in shear calculationsshall equal the depth of the beam plus theeffective depth of the slab with a minimum d =0.80 times the overall depth. The shear shall becalculated assuming full continuity for compositedead load and live load plus impact.For single span structures, use the shear designspacing at the 1/4 point for sections from the endof the beam to the 1/4 point. For continuousmulti-span structures, use the shear designspacing required from the 1/4 point to the pier forthe section from the 1/4 point to the abutment endto obtain a symmetrical reinforcing pattern for allgirders.403.07METHOD OF ANALYSISThe dead load shall be assumed to be unsupportedand carried by the girders only. Use of maskedstrands for debonding shall not be allowed.The location of the harped point of the strandshould be located as required by design with thepreferable locations being near the 1/10 of thespan as measured from the midspan of the girder.404 PRESTRESSED I-GIRDERS404.01GENERALPrecast Prestressed I-Girder Bridges shall bedesigned in accordance with AASHTOspecifications. Girders shall be designed byWorking Stress Method and checked by theUltimate Strength Method (Load Factor Design).The deck slab is to be designed by the WorkingStress Method using a maximum allowable stressof Fc=110 kg/cm², Class K 335.The slab and diaphragm dead load is to besupported by the girders only.The Girders are to be designed as a composite-section, simply-supported beams for Live Loadand Impact and all superimposed dead loads.Negative moment reinforcement is to be designedover the intermediate supports considering spancontinuity and all loads.Continuity designs will include shrinkage andcreep moments as required by AASHTO Article9.7.2.1.
404.02CONCRETEThe following concrete strengths are the desiredstrengths to be used. Higher strengths may beused if approved by the Abu Dhabi Roads SectionProject Manager.Initial f ′ci = 280 kg/cm² minimum.f ′ci = 350 kg/cm² maximum. Note:350 kg/cm² release strengths can beusually obtained within 18 hours, but require 4 to6 additional hours for each additional 7 kg/cm²required above 350 kg/cm². Permission isrequired from the Abu Dhabi Roads SectionProject Manager for release strengths above 350kg/cm² and final strengths above 420 kg/cm².Final f ′c = 350 kg/cm² minimumf ′c = 420 kg/cm² maximum
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 400-6The maximum allowable stresses are to be inaccordance with AASHTO except as modifiedbelow:Tension Load ConditionAllowableStressGirder DL + Prestress0Total Service Load 0.8ƒ'c404.03EFFECTIVE FLANGE WIDTH(AASHTO 9.8 AND 8.10.1)The effective flange width will be as specified byAASHTO except for Type V and standard andmodified type VI girders where the requirement of 12 times the slab thickness plus web thicknesswill be increased by 430 mm.404.04SHEARGirders will be designed for shear using the latestAASHTO Standard Specifications. The depth tobe used in the calculation of shear will be thedepth of the beam plus the depth of the of theslab. If composite action is fully developed, theshear will be calculated assuming full continuityfor composite dead load and live load plusimpact.404.05INTERMEDIATE DIAPHRAGMS(AASHTO 9.10)A single 300 millimeter thick intermediatediaphragm shall be placed at the midspan for allspans over 12 meters. For skews less than orequal to 10°, place the diaphragms parallel to theskew. For skews greater than 10º, thediaphragms shall be staggered and placed normalto the girders.404.06BEARING PADSLaminated neoprene bearing pads should be usedfor relatively light reactions and moderatesuperstructure movements.Pot type bearings should be used for heavyreactions, large superstructure movements andsuperstructure on horizontal curve alignment.Allow an extra 40 mm movement per 100 metersof girder length for long-term creep andshortening due to prestressing.Elastomeric bearing pads will be a maximumwidth of 50 mm less than the normal width of thebottom flange to accommodate the 20 mm sidechamfer and should be set back 50 mm from theend of the girder to avoid spalling of the girderends.404.07CREEP FACTORUse a creep factor of 3 when calculating longterm deflections.404.08FRAMES AND CONTINUOUSCONSTRUCTION (AASHTO9.7.2)Girders shall be designed as composite section,simple supported beams for live load plus impactand composite dead load. The superstructureshall be constructed continuous with the negativemoment reinforcing designed consideringcontinuity over intermediate supports for live loadplus impact and composite dead loads. Thepositive moment connection may be designedusing the method described in the PCApublication "Design of Continuous HighwayBridges with Precast, Prestressed ConcreteGirders". In determining the positive restraintmoment, use 30 days as the length, of timebetween casting the girders and deck closure. Thedevelopment length of the strands may be basedon the criteria contained in Report No. FHWA-RD-77-14, "End Connections of Pretensioned I-Beam Bridges" November 1974. In determiningthe number and pattern of
strands extended,preference shall be given to limiting the number of strands by increasing the extension length andalternating the pattern to increase constructability.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 400-7404.09DIFFERENTIAL SHRINKAGE(AASHTO 9.13.3.3)Differential shrinkage should be considered in thedesign when the effects become significant andwhen approved by the Project Manager.404.10METHOD OF ANALYSISAASHTO Type V and Type VI modified girdersshould be used in place of Type V and Type VIregular girders whenever possible.The theoretical build-up depth shall be ignored forcalculation of composite section properties.405 PRESTRESSSED VOIDED SLABS405.01END BLOCKSEnd Blocks should be 380 millimeters long withsufficient steel provided to resist the tensile forcesdue to concentrated prestressing loads.405.02DIAPHRAGMSDiaphragms shall be cast within the slab atmidspan for spans up to 12 meters and at thirdpoints for spans over 12 meters.405.03LATERAL TIESOne lateral tie shall be provided through eachdiaphragm located at the mid-depth of the section.405.04SHEAR KEYSAfter shear keys have been filled with anapproved non-shrink mortar, lateral ties shall beplaced and tightened.405.05BARRIERSBarriers shall have a 6 millimeter open joint at themidspan to prevent the barrier from acting as anedge beam and causing long term differentialdeflection of the exterior beam.406PRESTRESSED BOX BEAMS406.01END BLOCKSEND BLOCKS 450 MILLIMETERS LONGSHALL BE PROVIDED AT EACH ENDAND SUFFICIENT STEEL SHALL BEPROVIDED IN THE END BLOCKS TORESIST THE TENSILE FORCES DUE TOTHE PRESTRESSING LOADS.406.02DIAPHRAGMDiaphragms, cast within the beam, shall beprovided at the midspan for spans up to 15meters, at the third points for spans from 15 to 22meters and at quarter points for spans over 22meters.406.03LATERAL TIESOne lateral tie shall be provided through eachdiaphragm located at the mid-depth of the section.However, for the 990 millimeter and 1065millimeter deep sections, when adjacent units aretied in pairs for skewed bridges, in lieu of continuous ties, two ties shall be provided, locatedat the third points of the section depth.406.04SHEAR KEYSAfter shear keys have been filled with anapproved non-shrink, low slump mortar, lateralties shall be placed and tightened.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 500-1SECTION 500STRUCTURAL STEEL501DESIGN CRITERIA501.01GENERALStructural steel design criteria shall be asspecified in Section 10 of AASHTO except asclarified or modified in this manual.501.02DESIGN METHODSThe Service Load Design Method (AllowableStress Design) shall be used except that theStrength Design Method (Load Factor Design)may be used for major or unusual structures whenapproved.501.03MATERIALS (AASHTO 10.2)Materials shall conform with the requirements of AASHTO Article 10.2 with the selection basedon stress requirements and overall economy.The preferred maximum thickness of tensionflanges is 50 millimeters. Tension flanges thickerthan 50 millimeters shall be normalized.501.04ALLOWABLE FATIGUESTRESS (AASHTO 10.3.1)Splices, stiffeners, shear connectors and bracingdetails shall be designed using categories Athrough C details in order to limit the fatiguestress.Category E details shall not be used.501.05LOAD CYCLES (AASHTO 10.3.2)The stress cycle case to be used in AASHTOTable 10.3.2A shall be Case I.501.06CHARPY V-NOTCH IMPACTREQUIREMENTS(AASHTO 10.3.3)Where applicable, the Charpy V-Notch impactrequirements for structural steel shall be forTemperature Zone 1 at elevations less than 1800meters and Temperature Zone 2 at elevations1800 meters and higher, unless otherwise directedby the Project Manager.Intermediate stiffeners shall be placed only on theinside face of exterior girders.The number and location of girder shop and fieldsplices shall be determined so as to minimizefabricated and erected cost of the girders.All connections except field connections shall bewelded. ASTM A325M high strength bolts shallbe used for field connections.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 600-1SECTION 600EXPANSION ANDCONTRACTION601MOVEMENT CRITERIA601.01MOVEMENT RATINGProvisions shall be made in the design of structures to resist induced stresses or to providefor movements resulting from variations intemperature and anticipated shortening due tocreep, shrinkage or prestressing. Accommodationof thermal and shortening movements will entailconsideration of deck expansion joints, bearingsystems, restraining devices and the interaction of these three items.The main purpose of the deck joint is to seal the joint opening to obtain a watertight joint whileallowing for vertical, horizontal and/or rotationalmovement. The bearings are required to transmitthe vertical and lateral loads from thesuperstructure to the substructure units and toallow for movement in the unrestrained directions.Restraining devices are required to limit thedisplacement in the restrained directions.Improper design or construction of any of thesedevices could adversely affect the operation of theother devices.The required movement rating is equal to the totalanticipated movement (i.e. the difference betweenthe widest and the narrowest opening of a joint).The calculated movements used in determiningthe required movement rating shall be as specifiedin AASHTO except as modified below:Mean temperature and temperature ranges shallbe as specified in Section 201.08 of this manual.To allow for the effects of long term creep andshrinkage in precast prestressed concretemembers, the following additional shorteningshall be considered:Joints:20 mm per 100 meters.Bearings: 40 mm per 100 meters.To allow for the effects of long term creep andshrinkage in post-tensioned box girder bridges,the following additional shortening shall beincluded:Joints:40 mm per 100 meters.Bearings: 80 mm per 100 meters.602DECK JOINTS602.01GENERALThe movement rating for joints for steel structuresshall be based primarily on the thermal expansionand contraction characteristics of thesuperstructure, while for concrete structures theeffects of shortening due to creep and shrinkageand where applicable, prestressing shall also beadded. Movement ratings shall be based ontemperature variations as measured from theassumed mean temperature.Published movement ratings are usually based onthe difference between the maximum andminimum openings without consideration to therequired minimum installation width. Indetermining the movement rating, considerationmust be given to the installation width required toinstall the seal element.Other factors which should be considered indetermining the required movement rating includeconsideration of the effects of any skew,anticipated settlement and rotations due to liveloads and dead loads, where appropriate.Items requiring attention include:1) The type of anchorage system to be used.2) The method of joint termination at theends.3) The method of running joints throughbarriers, sidewalks and/or medians.4)
Physical limitation on size of joints.5) Susceptibility of joint to leakage.6) Possible interference with post-tensioninganchorages.7) Selection of appropriate modularproprietary systems that meet designrequirements.8) Forces applied to the surroundingconcrete by the joint.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 600-2Available types of joints include compressionseals, strip seals, and modular joints.Compression seal joints and strip seal joints aregeneric and should be detailed on the plans, bystandards and/or covered in the specialprovisions. Modular joints are proprietary andrequire that the designer specify allowable jointtypes and styles in the special provisions.Information concerning specific designparameters and installation details of modular joints should be obtained from literature suppliedby the manufacturer of the system. It is theresponsibility of the designer to review theproprietary joint literature and relatedmanufacturer's specifications to ensure that theselected joint types are properly specified andcompatible with the design requirements.The following features of joints should be shownon the plans:1) Blockout details showing a second pour,including blockout dimensions andadditional reinforcing required.2) Required end treatment in barriers orcurbs, including enough detail orexplanation to accommodate each of theproprietary systems selected (i.e. coverplates, etc.).3) Consideration to traffic control indetermining section pattern lengths.4) Movement rating.5) Assumed temperature and opening at timeof installation with temperature correctionfactors.6) Actual horizontal length of joint measuredfrom inside of barrier face to inside of barrier face corrected for skew.The following features of joints should bespecified in the specifications:1) For modular joints, the joint style, glandtype, steel edge beam material, and thename of a representative manufacturer.2) Method of measurement (by linear meterfrom face to face of barrier).A general discussion of joint types follows.However, for modular joints the actual selectionof the specific alternates should be made from thelist of approved joint types which can be obtainedfrom the Project Manager.602.02COMPRESSION SEALSThe compression seal element should have ashape factor of 1:1 (width to height) to minimizeside wall pressure. The size of the compressionseal shall be specified on the plans.Effective movement ratings for this type of jointrange up to 50 millimeters. Advantages for thistype of joint include its low cost, provenperformance and acceptance for use on pedestrianwalkways. However, this type of joint can not beunbolted and easily raised, generates pressure andis not good for high skews or horizontaldirectional changes.602.03STRIP SEALS
Strip seals should generally conform to the detailsshown in the structure detail drawing titled "StripSeal Joint". Proprietary alternates to this detailother than those shown on the detail drawing willnot be allowed.Effective movement ratings for this type of jointrange up to 100 millimeters. This type of joint isbest used when the movement rating is beyond thecapacity of compression seals and for largeskews. Strip seal joints will require cover platesfor pedestrian walkways.602.04MODULAR JOINTSModular joints are very complex joint systems.Effective movement ratings range from 100millimeters up to 750 millimeters. Modular jointsare the best choice for movement ratings over 100millimeters.603BEARINGS603.01GENERALUnlike joints, where the opening can be adjustedif the ambient temperature at the time of construction is different than the assumed meantemperature, bearings must be designed to beinstalled at temperatures other than the meantemperature. For this reason, the movement
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 600-3rating should be based on the full temperaturerange and not the rise or fall from a meantemperature.Calculation of the movement rating shall includethermal movement and anticipated shortening dueto creep, shrinkage and prestressed shortening.For cast-in-place post-tensioned concrete boxgirder bridges both the elastic and long termprestress shortening effects shall be considered.An initial offset of the top sliding surface from thecenterline of bearing should be calculated andshown on the plans so that the top sliding surfacewill be centered over the bottom sliding surfaceand the centerline of bearing after all shrinkage,creep and post-tensioning shortening has takenplace in the sperstructure.Permissible bearing types include neoprene strips,elastomeric bearing pads, steel bearings, slidingelastomeric bearings and high-load multi-rotational bearings (pot, disc or spherical).Neoprene strips, elastomeric bearing pads andsteel bearings are generic and shall be detailed onthe plans and/or covered in the standardspecifications and special provisions. High-loadmulti-rotational bearings are proprietary bearingtypes and require that the designer include aBearing Schedule in the plans. It is theresponsibility of the designer to review the StoredSpecification to ensure that the bearings areproperly specified and compatible with the designrequirements. Sliding elastomeric bearings areboth generic and proprietary in that a genericbearing should be designed and detailed on theplans with proprietary alternates allowed.All bearings types except elastomeric bearingpads shall be designed for impact.603.02NEOPRENE STRIPSNeoprene strips consist of a sliding plate on acontinuous neoprene pad. Where appropriate,neoprene strips are the preferred bearing type forpost-tensioned box girder bridges. However,neoprene strips are not appropriate for thefollowing applications: curved bridges, skewsgreater than 20 degrees, contributing spansgreater than 50 meters, where initial shorteningdue to prestressing is greater than 25 millimetersand where the movement rating including elasticshortening, long term creep and shrinkage andtemperature is greater than 40 millimeters.603.03ELASTOMERIC BEARINGPADSElastomeric bearing pads shall conform to therequirements of Section 14 of AASHTO. Bearingpads shall be designed to be constructed usingeither steel or fiberglass laminates, with thecontrolling case determining the size. Thefollowing data should be shown on the plans:Length, width and thickness of padDurometer HardnessDesign Method (A or B)Design LoadLow Temperature Zone (A, B or C)Elastomer Grade (0, 2 or 3)Shear ModulusGenerally, bearing pads shall be Durometer 60 -Elastormer with steel reinforcement.Normally Design Method A will be used indesign, however, where only steel reinforced padswill work Design Method B may be used providedthe special testing is performed.The following should be used as a guide fordetermining low temperature zones: Elevation (meters)ZoneBelow 900 A900-1800 B1800 and above CPads shall have a minimum thickness of 25millimeters and be designated in 10 millimeterincrements. The use of elastomeric bearing padsshould generally be limited to a thickness notgreater than 100 millimeters.
Holes will not beallowed in the pads.Width and length dimensions shall be detailed ineven 50 millimeter increments. When used withprestressed I-girders, pads shall be sized aminimum width of 50 millimeters less than thenominal width of the girder base to accommodatethe 20 millimeter side chamfer and shall be set
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 600-4back 50 millimeters from the end of the girder toavoid spalling of the girder ends.Elastomeric pads should not be used in caseswhere deck joints or bearings limit verticalmovements, such as in older style sliding steelplate joints or widenings where existing steelbearings are to remain.Where elastomeric bearing pads with greasedsliding plates are used on post-tensioned boxgirder bridges to limit the required thickness of the pad, the pad thickness should be determinedbased on temperature movements only, with theinitial and long term shortening assumed to betaken by the sliding surface.Elastomeric bearing pads are the preferredbearing type for new steel girders, precastprestressed girders and post-tensioned box girderbridges where neoprene strips are not appropriate.603.04STEEL BEARINGSSteel bearings may consist of rockers or fixed orexpansion assemblies which conform to therequirements specified in Section 10 of AASHTO.Steel bearings are not a preferred bearing typeand their use should normally be limited tosituations where new bearings are to match theexisting bearing type on bridge widening projects.603.05SLIDING ELASTOMERICBEARINGSSliding elastomeric bearings consist of an uppersteel bearing plate anchored to the superstructure,a stainless steel undersurface and an elastomericpad with a teflon coated upper surface. Theteflon surface shall be attached to a 10 millimeterminimum thick plate which is vulcanized to theelastomeric pad. The bearing accommodateshorizontal movement through the teflon slidingsurface and rotation through the elastomericbearing with the thickness of the elastomericbearing determined by the rotational and frictionforce requirements. Keepers may be used forhorizontal restraint of the pads. Vertical restraintmay be provided by anchor bolts with slottedkeeper plates or individual vertical restrainers asappropriate. The pad dimensions and all detailsof the anchorage and restraint systems shall beshown on the plans. The special provisionsshould allow for proprietary alternates.Sliding elastomeric bearings should be consideredfor applications where regular elastomeric bearingpads would exceed 100 millimeters in height orwhere special access details would be required forother proprietary bearings in such places ashinges.603.06HIGH-LOAD MULTI-ROTATIONAL BEARINGS603.06.01DescriptionHigh-load multi-rotational fixed bearings consistof a rotational element of the Pot-type, Disc-typeor Spherical-type. High-load multi-rotationalexpansion bearings consist of a rotational elementof the Pot-type, Disc-type or Spherical-type,sliding surfaces to accommodate translation andguide bars to limit movement in specifieddirections when required.Pot bearings consist of a rotational elementcomprised of an elastomeric disc totally confinedwithin a steel cylinder. Disc bearings consist of arotational element comprised of a polyetherurethane disc confined by upper and lower steelbearing plates and restricted from horizontalmovement by limiting rings and a shear restrictionmechanism. Spherical bearings consist of arotational element comprised of a sphericalbottom convex plate and mating spherical topconcave plate.These design criteria were prepared for the broadrange of normal applications and the specifiedlimits of loads, forces and movements. Thedesign and manufacture of multi-rotationalbearings relies heavily on the principles of engineering mechanics and extensive practicalexperience in
bearing design and manufacture.Therefore, in special cases where structuralrequirements fall outside the normal limits, abearing manufacturer should be consulted.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 600-5603.06.02Rotational RequirementsThe rotational requirements of these bearings istreated in a new way. Rotational requirements of the bearings, Rb, are determined by:Rb =Rs + RcwhereRb = Rotation capacity designed intothe bearing.Rs =Anticipated rotation of thestructure in service. (includes liveloads and rotations induced byconstruction/erection sequences).Rc = Rotation induced in the bearingby construction tolerances, 0.02radians maximum (see DesignCriteria 14).603.06.03UseUse of multi-rotational bearings is especiallyindicated where:1. Low profile, high load bearings arerequired. 2. Long span, curved, or skewed bridgesand other similar structures of complexdesign are required. 3. Long slender columns or light framesand members exhibit minimum stiffnessor rigidity. 4. The direction of rotation varies. 5. The direction of rotation cannot beprecisely determined. 6. Settlement of the substructure isanticipated. 7. Self aligning capabilities are required. 8. Load and rotation eccentricity does notsignificantly alter the net distribution of stress through the bearing and into thesubstructure and superstructure.9. It is desirable to reduce the momentapplied to truss or space frame panels.10.
Large movements are anticipated. 11. Economical, long life, or lowmaintenance bearings are desirable. 12. Regular elastomeric bearing padswould exceed 100 millimeters in height.603.06.04Design CriteriaSince special details are required to allow foraccess for inspection, repair or replacement of thebearings, the respacing of joints to eliminate theneed for use of these bearing types should beconsidered.Some structural considerations in use of multi-rotational bearings are listed below. Reference to"this specification" refers to the design criteriabelow.1. Vertical and horizontal loads shall beassumed to occur simultaneously. Allloads are service loads. Minimumvertical loads are for dead loads andsuperimposed dead loads excluding thefuture wearing surface. Maximumvertical loads are for dead loads,superimposed dead loads including thefuture wearing surface, and live loadsand impact. 2. The total recommended clearancebetween all guiding and guided slidingsurfaces is 1.5 millimeters in order tolimit edge stress on guiding interfaces. 3. Avoid specifying total spacing of morethan 1.5 millimeters between guidesand guided components where possible. 4. In specifying the horizontal forcecapacity of bearings, it is recommendedonly one fixed or guided expansionbearing shall be assumed to resist thesum of all the horizontal forces at eachabutment, bent, column, hinge or pier.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 600-65. Where feasible provide at least twofixed or guided expansion bearingseach able to resist all horizontal forcesat each abutment, column, hinge or pierfor design redundancy. 6. Some press-fit guide bar details incommon use have provenunsatisfactory in resisting horizontalloads. When analyzing these designs,consideration should be given to thepossibility of rolling of the bar in therecess. 7. Multi-rotational bearings should not beused at vertical loads less than 20% of their vertical capacity. Bearings forless than 20% vertical capacity requirespecial design. 8. Special consideration in bearing designshall be given where high horizontal tovertical load (above 0.30) isanticipated. 9. Frictional resistance of bearing slidesurfaces should be neglected whencalculating horizontal load capacity. 10. The installed alignment of bearingguiding systems relative to theanticipated movement direction of thestructure should be carefully consideredto avoid bearing guide system failure.Special studies or designs may berequired on curved or skewedstructures to ensure correct installation. 11. The substructure and superstructureshould be designed so as to remainrigid under all service conditions inareas around and in contact with thebearings, paying particular attention tothe use of stiffeners at extreme pointsof movements.12. The substructure and superstructuredesign should permit bearings to beremoved for inspection or rehabilitationby minimum jacking of the structure.Jacking points shall be provided in thestructural design.
13. The minimum Structure Rotational, Rs,of bearings covered in the specificationis 0.01 radians. Rs comprises liveloads and rotations induced byconstruction/erection sequences. 14. The maximum Construction Rotation,Rc (rotation induced by constructiontolerances), is 0.02 radians. Thedesigner may elect to specify a smallerRc than 0.02 radians but is cautionedto investigate the cost and practicalityof the changes contemplated. 15. Recommended coefficients of frictionfor structure design follows:Unfilled sheet or woven fiberPTFE/stainless steel 0.04Filled PTFE sheet/stainless 0.08The above coefficients of friction arebased on the average stress and limitsof edge stress of PTFE in thisspecification. Out of level installationswithin the limits of this specificationand normal in service oxidation of thestainless steel mating surface. Serviceconditions, where exceptional corrosionof the stainless steel mating surfacemay occur, will require specialassessment of the long term coefficientof friction.16. Pot, disc and spherical multi-rotationalbearings should not be mixed at thesame expansion joint or bent. Thediffering deflection characteristics anddiffering rotation characteristics mayresult in damage to the bearings and/orstructure. 17. Contract drawings and documentsshould contain a Bearing Schedule (SeeSection 603.07, Bearing Schedule).18. Some bearing tests are very costly toperform. Other bearing tests cannot beperformed because of the unavailabilityof test equipment. The following test
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 600-7requirements should be carefullyconsidered before specifying them:A) Vertical loads exceeding2,250,000 kg. B) Horizontal loads exceeding225,000 kg. C) The simultaneous applicationof horizontal and vertical loadswhere the horizontal loadsexceeds 75% of the verticalloads. D) Triaxial test loading. E) The requirement for dynamicrotation of the test bearingwhile under vertical load.603.07BEARING SCHEDULEA bearing schedule shall be included in thecontract drawings and documents and shallcontain the following as a minimum:1. A schedule of all minimum andmaximum vertical and horizontalservice loads. 2. Minimum Structure and ConstructionRotation requirements. 3. Magnitude and direction of movementsat all bearing support points. 4. Quantity, type (fixed, expansion orguided expansion). 5. Plan view, alignment and location of allbearing units. 6.
Allowable upper and lower bearingcontact pressure. 7. Fixing or anchorage details and/orrequirements. 8. Grades, bevels and slopes of allbearings. 9. Allowable coefficient of friction of slide surfaces. 10. Surface coating requirements and theappropriate specifications. 11. Seismic requirements, if any. 12. Uplift details, temporary attachmentsor other requirements. 13. Installation scheme. 14. Bearing preset details, if required.Design rotation, movement and otherrequirements in the Bearing Schedule should onlyrefer to the requirements of the structure wherethe bearings are to be used.604RESTRAINING DEVICES604.01GENERALRestraining devices are meant to prohibitmovement in a specified direction. Restrainingdevices shall be designed to resist the imposedloads including earthquake as specified inAASHTO and as modified in Section 200 of thismanual.Restraining devices could include concrete shearkeys or end blocks, horizontal or vertical cablerestrainers or mechanical restraining deviceswhich could be an integral part of a bearing or aseparate system. Restraining devices to prohibitvertical displacement at expansion ends, shall bedesigned to allow for inspection and futurereplacement of bearings.Allowable restraining devices include, but are notlimited to the following: Vertical FixedRestrainers,
Vertical Expansion Restrainers,External Shear Keys, Internal Shear Keys andKeyed Hinges.604.02VERTICAL FIXEDRESTRAINERSVertical fixed restrainers consist of cable andappropriate hardware and are designed to allow
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 600-8rotation but no translation in either horizontal orvertical directions.604.03VERTICAL EXPANSIONRESTRAINERSVertical expansion restrainers consist of cableand appropriate hardware and are designed toallow rotation and longitudinal translation but notransverse translation. Some limited verticaldisplacement is allowed to permit replacement of bearings if required.604.04EXTERNAL SHEAR KEYSExternal shear keys are reinforced concrete blocksdesigned to limit transverse displacement whileallowing longitudinal and rotational movements.External shear keys are preferred to internal shearkeys since they are more accessible for repairsand easier to construct.604.05INTERNAL SHEAR KEYSInternal shear keys are reinforced concrete blocksdesigned to limit transverse displacement whileallowing longitudinal and rotational movements.604.06KEYED HINGEA keyed hinge is a restraining device which limitsdisplacements in both horizontal directions whileallowing rotation.For a typical expansion seat abutment whererestraining devices are required, the restrainingdevices will consist of vertical expansionrestrainers and external shear keys.For a typical pinned seat abutment for a post-tensioned box girder bridge, restraining deviceswill consist of vertical fixed restrainers andexternal shear keys. For a typical pinned seatabutment for a prestressed girder bridge,restraining devices will consist of vertical fixedrestrainers and external or internal shear keys.For a typical expansion pier, restraining deviceswill consist of vertical expansion restrainers andinternal shear keys.For a typical pinned pier, restraining devices willconsist of vertical fixed restrainers and internalshear keys or a keyed hinge.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 700-1SECTION 700GEOTECHNICAL701FOUNDATIONS701.01GENERALThe main purpose of this section is to documentbridge design criteria as related to bridgefoundation geotechnical issues.Since problems requiring geotechnical andstructural expertise often result in confusionconcerning the responsibilities of each, anotherpurpose of this section is to define the role of thegeotechnical engineer and the bridge engineer indesign problems involving both fields.The usual procedure for designing bridgefoundation substructure units is as follows:The bridge design group will develop apreliminary location plan.The Geotechnical Engineer will conduct a siteinvestigation, identify borehole locations, drill andlog borings, perform soil testing as appropriate,plot the boring logs and summarize the results ina Geotechnical Report. The Geotechnical Reportwill include a Foundation Design Report whichidentifies the type of foundation recommended foreach substructure unit including the allowableloads and required depths.The Geotechnical Engineer is responsible forpreparing the boring logs on construction plans.They also prepare necessary special provisionsfor construction of the foundation elements.During construction of the bridge foundations, theGeotechnical Engineer oversees geotechnicaltesting, spread footing excavations and piling anddrilled shaft construction. They work closelywith bridge design group to jointly resolveproblems requiring redesign because of changedsite conditions. The bridge design group isresponsible for producing the structural designand construction documents for the substructureunits as part of the bridge plans.701.02SPREAD FOOTINGSWhere good soil materials exist near the surface,shallow foundations in the form of spreadfootings will normally be the recommendedfoundation type. For foundation units situated ina stream, spread footings shall only be used whenthey can be placed on non-erodible rock. Spreadfootings are normally not placed on embankmentmaterial.When spread footings are the recommendedfoundation type, the Geotechnical Report shallcontain the allowable bearing pressure, theelevation of the bottom of the footing and theestimated total settlement, differential settlementand time rate of settlement, if applicable.The bridge design group shall size the footing toensure that the allowable bearing pressure is notexceeded for any AASHTO Group Loading andthat the footing is properly sized and reinforced toresist the maximum applied moments and shears.The bottom elevations of spread footings shall beset at the recommended depth. The minimum topcover over the top of footings shall be 500millimeters. If the possibility for differentialsettlement is identified, the bridge designer shallensure that the entire structure is capable of structurally resisting the forces induced by thedifferential settlement.701.03PILE FOUNDATIONSWhen good foundation material is not locatednear the surface, when settlement is a problem, orfor foundation units located in streams wherescour is a problem, deep foundations will usuallybe recommended. One type of deep foundation isa driven pile. Driven piles may be either steel Hpiles, steel pipe piles or prestressed concrete piles.The other type of deep foundation is a bored pile.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 700-2701.04DRIVEN PILESThe Geotechnical Engineer is responsible forrecommending when driven piles are to be used,The type of driven pile to be used, the allowablecapacity of the pile, the estimated pile tipelevation and any special requirements necessaryto drive the piles. When steel piles are used, thecorrosive life of the pile will be reported in theGeotechnical Report. The Geotechnical Engineeris also responsible for running the WEAP87 waveequation computer program to determine thedriveability of the specified piles and to developcharts or other guidelines to be used byconstruction personnel to control the pile drivingprocess.The bridge design group is responsible forensuring that the allowable axial capacity is notexceeded for any AASHTO Group Loading andthat the pile can withstand the applied lateralloads.701.05BORED PILESA bored pile foundation consists of excavating around hole by machine, installing a metal casingor liner, placing a reinforcing cage in the casingor liner and then filling the casing or liner withconcrete.The Geotechnical Engineer is responsible forrecommending the minimum diameter of boredpile to be used and providing the necessaryinformation for determining the minimumrequired embedment below a specified elevationto develop the required axial load. TheGeotechnical Engineer is also responsible fordetermining the soil properties in each layer to beused in analyzing lateral loads and whether slurrymethods of construction may be utilized. If necessary, methods of testing the pile afterconcreting will be specified in the GeotechnicalReport.For the most part, bored piles will include atemporary casing or liner intended to preclude theintrusion of earth into the hole during the boringoperation and a permanent casing or liner thatwill remain in place and not be withdrawn duringthe concreting process. The temporary casingwill be advanced a sufficient depth into rock toprovide a seal against water inflow. Thetemporary casing shall be clean and free of waterbefore the permanent casings or liners, reinforcingsteel and concrete are placed.The bridge design group is responsible forensuring that the allowable axial capacity is notexceeded for any AASHTO Group Loading andthat the shaft can withstand the applied lateralloads.Unless specified otherwise in the GeotechnicalReport, the following minimum criteria should beused in designing bored pile foundations:1. Bored Piles shall be spaced a minimum of two diameters measured center to center of the holes plus 100mm. 2. Temporary and permanent casings or linersshall be designed to withstand handlingstresses, applicable concrete and surroundingsoil pressures, and shall be watertight. 3.
Vertical reinforcing should be detailed toprovide the minimum recommended clearancein AASHTO Article 4.6.6.2.1. In no caseshall the clearance between verticalreinforcing be less than 115 millimeters. 4. Reinforcement shall have a clear distance of not less than 50 millimeters from the insideface of the permanent casing or lining. 5. Horizontal ties should be spaced at 150millimeters minimum. 6. The footing, if applicable, shall be sized toextend a minimum of 200 millimeters fromthe edge of a bored pile.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 800-1SECTION 800RETAINING WALLS801DESIGN CRITERIA801.01GENERALRetaining walls are used when normal fill or cutslopes extend beyond acceptable limits. Wallsmay be classified in the following classes:Gravity Walls• Bin• Crib• Wire basket• Mass concreteCantilever Walls• ConcreteBraced Walls• Anchored Walls• Soldier pile and lagging• Tangent cylinder pilesMechanically Stabilized Walls• Reinforced Earth• VSL Retained Earth• Hilfiker-Reinforced Soil embankmentWalls shall be designed for a minimum factor of safety of 1.5 against sliding and 2.0 againstoverturning.The wall selection process includes identificationof types of walls appropriate for the site,evaluation of geotechnical behavior andproperties affecting wall behavior and selection of wall systems which fit all site constraints.Identification of alternate designs may beappropriate.In determining the
types of retaining wallscapable of fitting a particular site the followingshould be considered:• Availability of materials• Service life, maintenance, future use• Deflection tolerance• Ease of construction• Environmental/visual considerations• Special loading requirements• Settlement tolerance• Availability of space801.02POLICYThe following policy shall apply to retaining walldesign:1. Walls up to 6 meters high:The Consultant shall preparedrawings for cast-in-place concreteretaining walls utilizing the AbuDhabi Roads Section Standards andSpecifications.2. Walls over 6 meters high:The Consultant shall evaluate theapplicability of mechanicallystabilized wall systems and confirmtheir site-specific suitability. If theConsultant determines that amechanically stabilized wall systemis not appropriate due to soilsconditions or other site specificconditions, a complete cast-in-placeconcrete retaining wall design mustbe prepared for inclusion into the biddocuments.801.03RESPONSIBILITIESThe design of a retaining wall will usually involvethe efforts of three sections: Roadway DesignSection, Geotechnical Section, and the BridgeDesign Section.801.03.01Roadway Design SectionRoadway Design Section is responsible foridentifying the need for and limits of the retainingwalls. They will be responsible for providing aprofile adjacent to the top of the wall and the soilprofile line along the front face of the wall.Roadway Design is also
responsible foridentifying the acceptable limit of excavationrequired to maintain traffic and to design anydetours when required.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 800-2801.03.02Geotechnical SectionThe Geotechnical Section is responsible forinvestigating the site, drilling exploratory holes asrequired, determining the external stability of thesite and determining the material properties of theexisting soil and backfill. The GeotechnicalSection will also recommend soil strengthparameters and groundwater elevations forcomputing design lateral earth pressure. They arealso responsible for determining the maximumsafe slopes allowed during excavation.The Geotechnical Section also is responsible fordetermining the type of foundation required tosupport the wall loads, the allowable bearingpressure of the soil and the minimum requireddepths of the foundation units. This Sectiondetermines the soil properties to be used indetermining the lateral loads to be applied to thewall and determines the amount of settlement,differential settlement and the time rate of settlement for walls on compressible foundationsoils.The Geotechnical Section prepares appropriateSpecial Provisions for construction of theretaining walls and monitors construction of thefoundation elements, assisting the residentengineer as requested concerning geotechnicalissues. The Section works closely with the BridgeDesign Section on any structural design changesneeded during construction because of changedsite conditions.801.03.03Bridge Design SectionThe Bridge Design Section is responsible for thedesign of the structural elements of the wall, thelength of the wall and for producing the requiredconstruction plans, when requested by others, forany non-proprietary wall requiring structuralanalysis. The Bridge Design Section is alsoresponsible for determining whether shoring willbe required during construction based on theacceptable limits of excavation provided byRoadway Design and the safe excavation slopesprovided by Geotechnical. The Bridge DesignSection also selects walls which will handledifferential settlement, when present, and providesdetails for drainage on plans. Appurtenant trafficand/or pedestrian rails will also be designed anddetailed by the Bridge Design Section. ThisSection works with the Geotechnical Section onrequired structural design changes duringconstruction because of changed site conditions.801.04PROPRIETARY RETAININGWALLSWhen a proprietary retaining wall is chosen as anacceptable alternate, the special provisions willspecify the pre-approved wall systems which areacceptable for the particular application and site.The proprietary wall type is to be chosen from apre-approved list of wall types. The contractorwill be required to identify the alternate in his bid,with bid shopping after the award of the contractnot allowed.The Roadway Design Section will prepare plansshowing the location and extent of the walls andthe profile along the top of the wall and the soilprofile along the front face of the wall. The plansshould also show any restrictions regardingexcavation which may exist and requirements forappurtenant features such as traffic barrier,handrail or other attachments. Blockouts forlighting, signing, utilities and drainage structureswill also be detailed on the plans or identified tobe included with the proprietary plan submittals.The Geotechnical Section will prepare specialprovisions containing the design criteria to beused in evaluating the proprietary wall. As aminimum the following should be included:1.
The minimum factor of safety againstoverturning2. The minimum factor of safety against sliding3. Maximum coefficient of friction againstsliding4. Phi angle of the backfill5. Allowable bearing pressure6. Minimum design life7. Water table level8. Elevation of footing bottom9. Maximum tolerable deflection
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 900-1SECTION 900MISCELLANEOUS901TRAFFIC STRUCTURALSUPPORTS901.01GENERALLuminaires, traffic signals and sign supportsshall be designed using the AASHTOSpecifications for Structural Supports except asclarified or modified in this manual.901.02 WIND SPEEDMajor structural supports shall be designed forthe wind frequency of 160 kph.901.03 ALLOWABLE STRESSESThe, L /45.7 limitation on dead load deflectioncontained in Article 1.9.1(A) need not besatisfied since there is no scientific basis tosupport this limitation.For high mast light poles, the maximumdeflection shall be limited to 15% of the poleheight under wind load. The maximum allowableyield strength for design purposes shall be 4590kg/cm2.For all other applications, for steel with a yieldstrength greater than 3360 kg/cm2, the allowablestresses for design shall be limited to a yieldstrength of 3360 kg/cm2. This limitationindirectly places a limit on allowable deflectionsin an attempt to satisfy the criteria of Article1.9.1. This limitation also reduces the stresses inany high strength welds which are more brittleand subject to cracking due to fatigue fromvibrations.902UTILITIES IN STRUCTURES902.01GENERALWhere utility conflicts exist; water, power,telephone, cable TV and gas lines will berelocated as required for construction of theproject. Where it is feasible and reasonable tolocate utility lines elsewhere, attachment tostructures will not be permitted. Trenching in thevicinity of existing piers or abutments shall bekept a sufficient distance from footings toprevent undercutting of existing footings or toprevent disturbing foundation soils for futurefoundations.Where other locations prove to be extremelydifficult and very costly, utility lines exceptnatural gas may be allowed in the structures.Natural gas encroachments will be evaluatedunder the following policy:A. Cases where gas line attachments tostructures will not be considered under anycondition:1. Grade separation structures carryingvehicular traffic on or over freeways.2. Inside closed cell-type box girderbridges.3. High pressure transmission lines over 4kg/cm2and/or distribution lines of over150 millimeters in diameter.4.
Gas lines over minor waterway crossingswhere burial is feasible.B. Gas line attachments on structures will beconsidered under the following cases orconditions:1. Each case will be judged on its ownmerit with the utilities providingcomplete justification as to whyalternative locations are not feasible.2. Economics will not be a significantfactor considered in the feasibility issue.3. Open girder type structures across majorrivers.4. Pedestrian or utility bridges whereproper vented casings and other safetysystems are used.5. All lines are protected by casements.Provision for accommodation of relocated andfuture utilities on structures should follow thefollowing General Policy.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 900-2902.02POLICYSupport bracket details and attachments for allutilities will require Bridge Group approval.All approved utilities shall have individualsleeved casings, conduits or ducts as appropriate.All utilities carrying liquids shall be placed insidecasings through the entire length of the structure.The casing shall be designed to carry full servicepressure so as to provide a satisfactorycontainment in case the utility is damaged orleaks.Water lines, telephone conduits, power lines,cable TV lines, supports or other related itemswill not be permitted to be suspended below orattached to the exterior of any new or existingstructure.Product lines for transmitting volatile fluids willnot be permitted to be attached to or suspendedfrom or placed within any new or existingstructure.902.03UTILITY AGENCYRESPONSIBILITYThe utility agency is responsible for obtainingnecessary information regarding the proposedconstruction schedule for the project. Theagency shall submit a request including justification for attaching to the structure andpreliminary relocation plans including line massand support spacing as early as possible but nolater than the completion of preliminarystructural plans.The utility agency shall be responsible for thedesign of all conduits, pipes, sleeves, casings,expansion devices, supports and other relateditems including the following information:1. Number and size of conduits for power,telephone and cable TV lines.2. Size and schedule of carrier pipe forwater lines.3. Size and schedule of sleeved casings.4. Spacing and details of support brackets.5. Expansion device details.6. Total combined weight of carrier pipeand transmitted fluids, conduits, casings,support brackets, expansion joints andother related items.7. Design calculations.902.04 BRIDGE GROUPRESPONSIBILITYThe Bridge Group shall be responsible for andhave final approval authority for the followingaspects of the design:1. Determination of how many lines, if any,the structure can accommodate.2. Determination of where such lines shouldbe located within a structure.3. Determination of the size of the accessopenings and design of the requiredreinforcing.4. Determination of construction problemsrelated to required sequencing of project.5.
Tracking man-hours associated withutility relocations for cost recovery.Usually utilities will be accommodated byproviding individual access openings for casingsand sleeves to pass through. Access openingsshould be 50 millimeters larger than the diameterof the casings or sleeves and spaced as requiredby structural considerations.For box girder bridges, access openings shouldbe located as low as possible but no lower than250 millimeters above the top of the bottom slabto allow for support brackets to be supportedfrom the bottom slab. Where possible all utilitiesshall be supported from the bottom slab for boxgirder bridges.For girder bridges, the utilities shall not beplaced in the exterior girder bay and shall besupported from the deck slab.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 900-3903 FALSEWORK POLICY FORBRIDGE CONSTRUCTION903.01FALSEWORK REQUIREMENTSTo ensure that traffic handling is given properconsideration in the early design stages, it isnecessary to identify traffic handling andfalsework assumptions in the Bridge SelectionReport. If falsework is to be used, the horizontaland vertical clearances shall be shown on theGeneral Plan. Usually, one of the followinglisted conditions will prevail:1. Traffic will be routed around constructionsite.2. Traffic will pass through construction site.A. No falsework allowed over traffic. Thisrestriction would require precastconcrete or steel superstructure with fieldsplices located clear of traffic.B. Stage construction required. Stageconstruction must be detailed on theplans. Construction joints or hingeswould be required.C. Falsework openings required. The sizeand number of openings must be shown.General discussions and a table of falsework openings are covered under "Falsework Clearances".903.02FALSEWORK USEWhen traffic must pass through the constructionsite, three possible conditions exist. Condition2.A. is limited to sites which can be spanned byprecast members or where steel is competitive incost. The staged construction option of Condition 2.B. is not always feasible while thepresence of a hinge is a permanent disadvantage.Condition 2.C. is used for all other cases when itis necessary to route traffic through theconstruction site. The elimination of permanentobstructions by using longer spans andeliminating shoulder piers will usually outweighobjections to the temporary inconvenience of falsework during construction.903.03FALSEWORK CLEARANCESFor cast-in-place structures, the preferred methodof construction is to route traffic around theconstruction site and to use earth fills forfalsework. This provides an economical solution,a safe working area and eliminates possibleproblems associated with the design, approval,construction and performance of falsework including the possible effect of excessivedeflections of falsework on the structure.When the street or highway must be kept openand detours are not feasible, falsework shall beused with openings through which traffic maypass. Because the width of traffic openingsthrough falsework can significantly affect costs,special care should be given to minimizingopening widths consistent with traffic and safetyconsiderations. The following should beconsidered:1. Staging and traffic handlingrequirements.2. The width of approach roadway that willexist at the time the bridge isconstructed.3.
Traffic volumes and percentage of trucks.4. Vehicular design speed.5. Desires of local agencies.6. Controls in the form of existing facilities.7. The practical problems of falsework construction.8. Consideration of pedestrianrequirements.The minimum width of traffic openings throughfalsework for various lane and shoulderrequirements shall be as shown in Table 900.01.The resulting falsework span shown in Table900.01 is the minimum span. When temporaryconcrete barrier is used, 0.6 meters of safetymargin per side is allowed for deflection. Whenblocked-out "W" beam is used, 1.2 meters of safety margin per side is allowed for deflection.The normal spans may be reduced or increased if other forms of protection are used depending onthe required space for installation and deflection.The actual width of traffic openings throughfalsework and the resulting falsework span to beused in design shall be determined by the Abu
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 900-4Dhabi Roads Section Project Manager and shallbe stated in the Bridge Selection Report.To establish the grade line of a structurespanning an existing street or highway,allowance must be made for depth of falsework,where used, to provide the clearance needed topermit traffic through the work area duringconstruction. The minimum allowances to bemade for depth of falsework shall be as shown inTable 900.02 and shall be based on the actualfalsework openings determined by the Abu DhabiRoads Section Project Manager.The minimum vertical clearance for falsework over freeways shall be 4.50 meters.Where the vertical falsework clearance is lessthan 4.50 meters, advance warning devices shallbe specified or shown on the plans. Such devicesmay consist of flashing lights, overhead signs,over-height detectors or a combination of these orother devices. A standard insert sheet has beendeveloped for the details of the over-heightdetectors or safety beams. Providing for thesedevices in the specifications or on the plans shallbe the responsibility of the Abu Dhabi RoadsSection Project Manager. Note to bridge designer: Special considerationshall be given to limit the maximum allowabletension in a precompressed tensile zone of post-tensioned box girder bridges supported on falsework with large openings.Table 900.01FALSEWORK SPAN REQUIREMENTS Detour Roadway Minimum Width Resulting Falsework Span (1) Facility to No. Shoulder of Traffic Temporary Blocked-out be spanned Lanes Widths Opening (1) Conc. Barrier "W" beam(meters) (meters) (meters) (meters)Freeway & 1 0.6 & 0.64.87.28.4Non-Freeway 2 0.6 & 0.68.410.812.03 0.6 & 0.612.014.415.64 0.6 & 0.615.618.019.2 NOTES:(1)Traffic Opening and Falsework Span are measured normal to detour centerline.Table 900.02FALSEWORK DEPTH REQUIREMENTSFalsework Opening 7.28.410.812.014.415.618.019.2(meters)Minimum RequiredFalsework Depth(mm)Max 3365 kg/m485510585815915107010951145per girder line3365 - 4580 kg/m5105608158901070112011451170per girder line NOTES:1. DL based on 2550 kg/m3concrete.2. Table 900.02 is based on the superstructure concrete being designed for zero tensile stress at the falsework openings. Superstructures designed with concrete tensile stresses can significantlyincrease the required falsework depths shown in the table and amount of falsework required.
3. Structures with greater than 4580 kg/m Dead Load per girder line will require specialconsiderations for required falsework depths.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 900-5904CONSTRUCTION JOINTGUIDELINES FOR BRIDGECONSTRUCTION904.01GENERALThe type of structure and method of construction,combined with sound engineering judgment,should be used in determining the number andlocation of superstructure construction joints.The use of construction joints should beminimized for ease of construction andsubsequent cost savings. Some items whichshould be considered are: 1. Method of construction - earthen fillfalsework, conventional falsework orgirder bridge without falsework.2. Phase construction because of physicalconstraints such as traffic handling.3. Span length and estimated rotation anddeflection.4. Degree of fixity at abutments and piers.5. Effects of locating a construction joint ina region of negative moment.6. Volume of concrete to be poured withouta joint.7. Consequences of continuous pour,including adverse effects caused by abreakdown during the pour.Some important requirements regardingconstruction joints contained in the StandardSpecifications are as follows:1. The sequence of concrete placementshall be as shown on the project plansor as approved by the Engineer whennot shown on the project plans.2. The rate of concrete placement andconsolidation shall be such that theformation of cold joints withinmonolithic sections of any structure willnot occur.3. The rate of concrete placement formajor structures shall not be less than27 cubic meters per hour unlessotherwise specified or approved inwriting by the Engineer.4. Placement of the deck concrete shall bein accordance with the placing sequenceshown on the project plans.5. The Contractor shall submit drawingsshowing the placement sequence,construction joint locations, directionsof the concrete placement and any otherpertinent data to the Engineer for hisreview. The drawing shall be submittedat least four weeks prior to the date of deck placement.6.
Construction joints shall be placed inthe locations shown on the project plansor as approved by the Engineer.7. All construction joints shall beperpendicular to the principal lines of stress and in general located at points of minimum shear and moment.904.02LONGITUDINALCONSTRUCTION JOINTSLongitudinal construction joints in bridge decksand/or superstructures should be identified asoptional unless required by construction phasing.The optional deck joints should be placed on lanelines or at center of structure. All longitudinalconstruction joints should be keyed.904.03 PRECAST CONCRETE GIRDERBRIDGESPrecast concrete girder bridges made continuousover supports shall have transverse construction joints placed so that the girders undergo theirpositive moment deflections prior to the finalpour over the negative moment areas of the fixedpiers or abutments. There shall be no horizontalconstruction joint between fixed pier diaphragmor abutment diaphragm and the deck.Girder bridges will usually require details on theplans showing a plan view with joint locations,deck pour sequence and direction of pour, if required. There should be a minimum of 12hours between adjacent pours. A continuouspour from abutment to abutment will not beallowed. Construction joints where requiredshould be parallel to the centerline of the pier.Their location will be near the point of minimumdead load plus live load moment and shear. Thisdistance is generally one-quarter of the spanlength from the pier if the adjacent spans areapproximately equal length.
ROADWAY DESIGN MANUAL – Roads and BridgesPart 3 900-6904.04STEEL GIRDER BRIDGESThe effects of uplift and allowing a continuouspour should be considered when developing deck pour schedules for multi-span continuous steelgirder bridges. The required rate of pour shouldbe compared to the quantity of concrete to beplaced and the potential for poured sections to setup and develop tensile stresses from pours inadjacent spans shall be considered whendetermining the need for construction joints.Consideration must be given to the potential fornegative moment stresses in the deck due toplacement of positive moment pours in adjacentspans.Girder bridges will usually require details on theplans showing a plan view with joint locations,deck pour sequence and direction of pour, if required. Except where otherwise required, thereshould be a minimum of 12 hours betweenadjacent pours. Construction joints, whererequired, should be parallel to the centerline of the pier. Their location should be near the pointof dead load counterflexure.904.05CAST-IN-PLACE BOX GIRDERBRIDGESBox girder bridges made continuous oversupports shall have transverse construction jointsplaced so that the webs undergo their positivemoment falsework deflections prior to the finalpour over the negative moment areas of the fixedpiers or abutments if the superstructureformwork is supported on conventionalfalsework. The transverse construction jointsmay be omitted if the superstructure formwork issupported on earthen fill. The webs and alldiaphragms should be poured concurrently withthe bottom slab. Transverse construction jointswhere required should be parallel to thecenterline of the pier. Their location near theinflection point is generally one-quarter of thespan length from the pier if the adjacent spansare approximately equal length
