the 2010 highway capacity manual richard dowling 1
TRANSCRIPT
The2010 Highway Capacity Manual
Richard Dowling
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The Highway Capacity Manual
4 Editions & 1 Update from 1950 to 2000
HCM 2000 24,500 copies distributed (14% metric) Another 500 copies for the 2011 PE Exam
Most fervent readers: Students and software developers
Everybody using traffic analysis software uses HCM
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Major Changes for 2010
Guidance on Integrating Microsimulation and HCM
Multimodal (Complete Streets) LOS Analysis
Software
Active Traffic Management
Partially Electronic Format
New HCM 2010 Support Website
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Presentation Outline
Content, Format, Schedule, Software
Technical Innovations Uninterrupted flow facilities (freeways, rural
highways) Interrupted flow facilities (urban streets,
signals)
Alternative Methods (microsimulation)
Active Traffic Management
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- It won’t come entirely in printed form- One part will come entirely in electronic form- Software: source code available to all- A website for extra materials
Format and Content5
Organization of Manual
Volume 1 – Concepts
Volume 2 – Uninterrupted Flow Facilities Freeways, rural highways, rural roads
Volume 3 – Interrupted Flow Facilities Urban arterials, intersections, roundabouts Signals at freeway interchanges, Bicycle and Pedestrian paths
Volume 4 – Supplemental Materials
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Vol.1 – Concepts of Capacity
Target Audience: Managers, Students Nine chapters that cover…..
Concepts Traffic flow, capacity, quality of service Modal characteristics
Capacity Analysis Applications How to apply the HCM How and when to use microsimulation Interpretation and presentation of results
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Vol. 2 – Uninterrupted Flow Facilities Target Audience: technical people
Six chapters on: Freeways and their component sections
Basic sections, ramp merge/diverge, weaving Multi-lane rural highways Two-lane rural roads
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Vol. 3 Interrupted Flow Facilities
Target Audience: Technical and professional people
Eight chapters on: Urban arterials Signalized intersections Unsignalized intersections Roundabouts Signals at freeway interchanges Bike and pedestrian paths
Multimodal Level of Service
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Vol. 4 – Supplemental Materials Target Audience: Engineers and
programmers
12 chapters, all electronic, on the web More detailed descriptions of methods Worked example problems
Annotated software source code
Technical reference library
HCM Application Guide
New: Active Traffic Management
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Software
Software Source code available to all Illustrates how to program the methods Can be used to verify commercial software
Will not compete with commercial software Will have very limited user interface Will work only for simple and limited
example problems
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Website12
Publication Schedule
In TRB Production
Publication December 2010
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Uninterrupted Flow FacilitiesInterrupted Flow Facilities
Technical Innovations14
Technical Innovations• New speed-flow equations• New freeway analysis software• New weaving method• Service volume tables
Uninterrupted Flow Facilities
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Freeway Speed-Flow Curves16
Free-Flow Speed No longer function of number of lanes Ramp density substituted for interchange
density
New curve for 75 mph free-flow speed
Speed does not drop until 1200 vph/ln reached
17 Source: Draft HCM 2010 Materials, Kittelson & Associates
Weaving Sections18
Changes to Current Method New weaving section types New method for estimating speed Weaving length dependent on demands. New method for estimating capacity
LB
LSLB
LS
Freeway Facility Analysis19
Modifications to reflect changes in other chapters
New software implementation (FREEVAL)
Updated capacity information for: Work Zones Weather (rain, snow, wind, visibility) Incidents
Analysis Over Time & Space20
D/C SS 1 SS 2 SS 3 SS 4 SS 5 SS 616:00 0.68 0.75 0.72 0.72 0.80 0.7316:30 0.75 0.85 0.82 0.82 0.93 0.8217:00 0.87 0.97 0.90 0.90 1.03 0.9317:30 0.82 0.90 0.85 0.85 0.98 0.8518:00 0.73 0.78 0.73 0.73 0.80 0.7018:30 0.58 0.62 0.58 0.58 0.62 0.60MPH 16:00 63 62 63 63 61 6216:30 62 60 61 61 58 6117:00 60 57 59 29 41 5817:30 61 59 19 15 35 6018:00 62 62 62 27 48 6318:30 64 64 64 64 64 64
FREEVAL Outputs (Speed)21
1
3
50.00
10.00
20.00
30.00
40.00
50.00
60.00
1 2 3 4 5 6 7 8 9 10 11
Time Interval
Spee
d (m
i/hr
)
Segment Number
Space Mean Speed Contours (mi/hr)
50.00-60.00
40.00-50.00
30.00-40.00
20.00-30.00
10.00-20.00
0.00-10.00
Service Volume Tables
Rural Freeway ADT’s (1000’s)
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Multi-lane Highways
Bicycle LOS analysis added
Service volume tables
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Two Lane Highways
Two-way analysis methodology dropped.
Some revisions to curves and tables.
New road class added for built-up areas. LOS based on % free-flow speed (FDOT)
Bicycle LOS on two-lane highways.
Service volume tables
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Technical Innovations:• New multimodal level of service method• New methods for arterials and signals• New method for signals in an interchange• New method for roundabouts
Interrupted Flow Facilities25
Multimodal Level of Service
Simultaneous analysis of LOS for auto drivers, bus riders, bicyclists, pedestrians.
A method for allocating scarce street right-of-way to the various modal users of the street.
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Sharing the Street – Complete Streets
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10’ 12’5’ 5’8’5’ 5’8’
70 ft ROW
12’
Mode Before After
Auto C D
Bus B C
Bicycle F D
Pedestrian E E
Before
After
Urban Street Analysis
Predicts Stops (New), Speed, Queues
Models signal coordination force offs, yields
Mixed street: signal, stops, roundabout
Sensitive to access management driveways, median breaks
Service Volume Table
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Urban Street Service Volumes
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Signalized Intersection Updates Incremental queue analysis (IQA)
Traffic actuated signals Min. green, passage time, recall, dual entry,
Dallas phasing, simultaneous gap out, detector length.
Left turn queue overflow check (New)
Volume/capacity ratio check (New)
Level of service for bicycles and pedestrians (New)
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Incremental Queue Analysis31
Que
ued
Veh
icle
s
Time
Delay polygon for shared left-through lane with permitted lefts
Old
New
Left Turn Overflow Check (New)
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If left turn overflow occurs, review results
Volume/Capacity Ratio Check
if: v/c > 1.00
Then the signalized intersection LOS is “F”
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Two-Way Stop Updates
Extended to 6-lane arterials.
U-turns
Analysis of shared lanes, short lanes
Pedestrian crossings analysis
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All Way Stop Updates
Queuing model added
Explicit guidance for 6-lane streets
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Roundabouts Update
New methodology based on US Research NCHRP Report 572
U.S. Capacities lower than rest of world
LOS based on delay Same thresholds as for unsignalized
intersections Roundabouts held to higher standard than
signals
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Roundabout Capacity37
0
200
400
600
800
1,000
1,200
1,400
0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000
Conflicting Flow Rate (pc/ h)
Capaci
ty (
pc/
h)
Dashed regression extrapolated beyond the data
Capacity of one-lane entry or right lane of two-lane entry against two conflicting lanes
Capacity of left lane of two-lane entry against two conflicting lanes
Capacity of one-lane or either lane of two-lane entry against one conflicting lane
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates
0
200
400
600
800
1,000
1,200
1,400
0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000
Conflicting Flow Rate (pc/ h)
Capaci
ty (
pc/
h)
Dashed regression extrapolated beyond the data
Capacity of one-lane entry or right lane of two-lane entry against two conflicting lanes
Capacity of left lane of two-lane entry against two conflicting lanes
Capacity of one-lane or either lane of two-lane entry against one conflicting lane
Capacity: 1 lane
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates
0
200
400
600
800
1,000
1,200
1,400
0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000
Conflicting Flow Rate (pc/ h)
Capaci
ty (
pc/
h)
Dashed regression extrapolated beyond the data
Capacity of one-lane entry or right lane of two-lane entry against two conflicting lanes
Capacity of left lane of two-lane entry against two conflicting lanes
Capacity of one-lane or either lane of two-lane entry against one conflicting lane
Capacity: 2x1 lane
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates
0
200
400
600
800
1,000
1,200
1,400
0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000
Conflicting Flow Rate (pc/ h)
Capaci
ty (
pc/
h)
Dashed regression extrapolated beyond the data
Capacity of one-lane entry or right lane of two-lane entry against two conflicting lanes
Capacity of left lane of two-lane entry against two conflicting lanes
Capacity of one-lane or either lane of two-lane entry against one conflicting lane
Capacity: 1x2 lane
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates
0
200
400
600
800
1,000
1,200
1,400
0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000
Conflicting Flow Rate (pc/ h)
Capaci
ty (
pc/
h)
Dashed regression extrapolated beyond the data
Capacity of one-lane entry or right lane of two-lane entry against two conflicting lanes
Capacity of left lane of two-lane entry against two conflicting lanes
Capacity of one-lane or either lane of two-lane entry against one conflicting lane
Capacity: 2x2 lane
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates
Interchange Ramp Terminals
Analysis of Diamonds, Par-clos, Roundabouts
Methodology for choosing interchange types
Lost capacity due to: Queue spillbacks Uneven lane utilization Demand starvation
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When and how to apply microsimulation.Comparing microsimulation results to HCM results
Alternative Methods43
Chapter 6: HCM and Alternative Tools Planning Methods Based on the HCM
Alternative Methods (Microsimulation) Traffic modeling concepts Application guide Framework to apply HCM + microsimulation Comparison of performance measures Selection of traffic models
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Chapter 7 Interpreting Results
Uncertainty and Variability Concepts, Sources, Sensitivity Analysis Uncertainty and Sensitivity of HCM results
Comparing HCM and Microsimulation Results Framework for comparing HCM/microsim
results Specific guidance provided in facility
specific chapters
Presentation of HCM/Microsimulation Results Significant digits for reporting
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Microsimulation vs HCM Delay
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Time
AccumulatedVehicles
Arriva
ls
Departures
AnalysisPeriod
QueueDissipation
Time
HCMDelay
Microsimulation
Delay
New chapter on the continuous real time monitoring and management of both demand and capacity
Active Traffic Management47
Active Traffic Management
ATM is a comprehensive approach to optimizing the operational performance of the roadway system through monitoring and control of systems operations and demands.
Examples Demand Metering, Congestion Pricing,
Managed Lanes, Adaptive Control, Speed Harmonization, Traveler Information Systems, Incident Management, Work Zone Management
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Active Traffic Management
Provides basic information on active traffic management measures
Provides references from the literature
Describes applicability of HCM or microsimulation methods to evaluation
New methodology coming in one year
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Conclusion – The New HCM
New tools for multimodal planning
Guidance on the use of microsimulation
New methods for freeways and streets
Service volume tables for planning applications
New material to aid software programmers
Information on Active Traffic Management
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Questions/Comments
Richard Dowling Dowling Associates, Oakland, CA 510-839-1742 ext 120 [email protected]
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