hcm2000
TRANSCRIPT
Highway Capacity Manual 2000
A 4-Hour Introduction to HCM2000…
Part II: ConceptsPart II: Concepts
Part I - IntroductionPart II - ConceptsPart III – MethodologiesPart IV - Corridor and Area-Wide AnalysesPart V - Simulation and Other Models
Highway Capacity Manual 2000
Part II ChaptersPart II Chapters
n 7: Traffic Flow Parameters (13)n 8: Traffic Characteristics (32)n 9: Analytical Procedures Overview (12)n 10: Urban Street Concepts (51)n 11: Pedestrian and Bicycle Concepts (21)n 12: Highway Concepts (20)n 13: Freeway Concepts (30)n 14: Transit Concepts (33)
n 7: Traffic Flow Parameters (13)n 8: Traffic Characteristics (32)n 9: Analytical Procedures Overview (12)n 10: Urban Street Concepts (51)n 11: Pedestrian and Bicycle Concepts (21)n 12: Highway Concepts (20)n 13: Freeway Concepts (30)n 14: Transit Concepts (33)
Highway Capacity Manual 2000
Part II Purpose and ContentPart II Purpose and Content
n To educate HCM users on LOS concepts and use• Facility-type concepts• Discussion of typical capacity parameters• Review of precision and accuracy of variables• Suggested default values• Sample service volume tables• Quick-estimation method for signalized
intersections (Chapter 10)
n To educate HCM users on LOS concepts and use• Facility-type concepts• Discussion of typical capacity parameters• Review of precision and accuracy of variables• Suggested default values• Sample service volume tables• Quick-estimation method for signalized
intersections (Chapter 10)
Highway Capacity Manual 2000
7: Traffic Flow Parameters7: Traffic Flow Parameters
n Uninterrupted Flow• Volume and flow-rate• Speed• Density• Headway and spacing• Relationships among
basic parameters
n Uninterrupted Flow• Volume and flow-rate• Speed• Density• Headway and spacing• Relationships among
basic parameters
Highway Capacity Manual 2000
n Interrupted Flow• Signal Control• Stop- or Yield-Controlled
Intersections• Speed• Delay• Saturation Flow Rate
and Lost Time• Queuing
n Interrupted Flow• Signal Control• Stop- or Yield-Controlled
Intersections• Speed• Delay• Saturation Flow Rate
and Lost Time• Queuing
7: Traffic Flow Parameters7: Traffic Flow Parameters
Highway Capacity Manual 2000
n Vehicle and Human Factors• Vehicles• Drivers• Pedestrians• Bicycles• Bus/LRT
n Vehicle and Human Factors• Vehicles• Drivers• Pedestrians• Bicycles• Bus/LRT
8: Traffic Characteristics8: Traffic Characteristics
Highway Capacity Manual 2000
n Demand and Volume• Temporal variation• Analysis hour• Spatial distributions
– Directional– Lane
n Demand and Volume• Temporal variation• Analysis hour• Spatial distributions
– Directional– Lane
8: Traffic Characteristics8: Traffic Characteristics
Highway Capacity Manual 2000
n Measured and Observed Values• Volume/Flow Rate• Speed• Headway• Saturation flow• Bus flow• Passenger flow
n Measured and Observed Values• Volume/Flow Rate• Speed• Headway• Saturation flow• Bus flow• Passenger flow
8: Traffic Characteristics8: Traffic Characteristics
Highway Capacity Manual 2000
n Precision and Accuracy• Statistical accuracy of many methods not
known• Validation of current procedures generally not
statistically adequate• Stochastic properties of traffic should be
considered in judging appropriate degrees of complexity and sensitivity
n Precision and Accuracy• Statistical accuracy of many methods not
known• Validation of current procedures generally not
statistically adequate• Stochastic properties of traffic should be
considered in judging appropriate degrees of complexity and sensitivity
9: Analytical Procedures Overview9: Analytical Procedures Overview
Highway Capacity Manual 2000
HCM2000 StructureHCM2000 Structure
Highway Capacity Manual 2000
n Hourly and daily volume equivalencies• PHF• K-factor• D-factor
n Use and development of local defaultsn Use and development of service volume
tables
n Hourly and daily volume equivalencies• PHF• K-factor• D-factor
n Use and development of local defaultsn Use and development of service volume
tables
9: Analytical Procedures Overview9: Analytical Procedures Overview
Highway Capacity Manual 2000
n Urban Streets• Flow characteristics• Levels of service• Required input data and estimated values• Service volume table
n Urban Streets• Flow characteristics• Levels of service• Required input data and estimated values• Service volume table
10: Urban Street Concepts10: Urban Street Concepts
Highway Capacity Manual 2000
Example Service Volume TableExample Service Volume Table
Highway Capacity Manual 2000
n Signalized Intersections• Characteristics• Capacity and LOS• Required input data and
estimated values• Service volume table
n Signalized Intersections• Characteristics• Capacity and LOS• Required input data and
estimated values• Service volume table
10: Urban Street Concepts10: Urban Street Concepts
Highway Capacity Manual 2000
Required Signal DataRequired Signal Data
Highway Capacity Manual 2000
Intersection Control TypeIntersection Control Type
Highway Capacity Manual 2000
Example Service Volume Table:Signalized Intersection
Example Service Volume Table:Signalized Intersection
Highway Capacity Manual 2000
n Unsignalized Intersections• TWSC, AWSC, and roundabouts
– Characteristics– Capacity– Performance measures– Service volume tables
n Unsignalized Intersections• TWSC, AWSC, and roundabouts
– Characteristics– Capacity– Performance measures– Service volume tables
10: Urban Street Concepts10: Urban Street Concepts
Highway Capacity Manual 2000
Example Service Volume Table:TWSC Intersection
Example Service Volume Table:TWSC Intersection
Highway Capacity Manual 2000
Quick Estimation Method:Signalized Intersections
Quick Estimation Method:Signalized Intersections
n Determines critical v/c, signal timing, and delay• Consists of six steps:
– 1) assemble input data– 2) determine left-turn treatment– 3) compute lane volumes– 4) estimate signal timing plan– 5) calculate critical v/c– 6) calculate average delay
n Determines critical v/c, signal timing, and delay• Consists of six steps:
– 1) assemble input data– 2) determine left-turn treatment– 3) compute lane volumes– 4) estimate signal timing plan– 5) calculate critical v/c– 6) calculate average delay
Highway Capacity Manual 2000
Quick Estimation Method:Signalized Intersections
Quick Estimation Method:Signalized Intersections
n Input Data Requirements (some may be estimated):• Volumes• Lanes• Adjusted saturation flow rate• Left-turn treatment• Cycle length (min and max)• Lost time• Green time• Coordination (yes or no)• PHF• Parking (yes or no)• Area type (CBD or not)
n Input Data Requirements (some may be estimated):• Volumes• Lanes• Adjusted saturation flow rate• Left-turn treatment• Cycle length (min and max)• Lost time• Green time• Coordination (yes or no)• PHF• Parking (yes or no)• Area type (CBD or not)
Highway Capacity Manual 2000
n Terminology and principlesn Characteristicsn Performance measuresn Required input data and estimated valuesn Service volume tables
n Terminology and principlesn Characteristicsn Performance measuresn Required input data and estimated valuesn Service volume tables
11: Pedestrian and Bicycle Concepts11: Pedestrian and Bicycle Concepts
Highway Capacity Manual 2000
11: Pedestrian and Bicycle Concepts11: Pedestrian and Bicycle Concepts
Highway Capacity Manual 2000
Example Service Volume Table:Pedestrian Sidewalk
Example Service Volume Table:Pedestrian Sidewalk
Highway Capacity Manual 2000
LOS Criteria for Uninterrupted Bicycle Facilities
LOS Criteria for Uninterrupted Bicycle Facilities
Highway Capacity Manual 2000
12: Highway Concepts12: Highway Concepts
n Multilane highways• Capacity• Free-flow speed• Parametric relationships• Factors affecting free-flow speed• Factors affecting flow rate• LOS• Required input data and estimated values• Service volume table
n Multilane highways• Capacity• Free-flow speed• Parametric relationships• Factors affecting free-flow speed• Factors affecting flow rate• LOS• Required input data and estimated values• Service volume table
Highway Capacity Manual 2000
Speed-Flow Relationships onMultilane Highways
Speed-Flow Relationships onMultilane Highways
Highway Capacity Manual 2000
Example Service Volume Table:Multilane Highway
Example Service Volume Table:Multilane Highway
Highway Capacity Manual 2000
12: Highway Concepts12: Highway Concepts
n Two-Lane Highways• Classification• Basic relationships• Passing lanes• LOS• Required input data and estimated values• Service volume table
n Two-Lane Highways• Classification• Basic relationships• Passing lanes• LOS• Required input data and estimated values• Service volume table
Highway Capacity Manual 2000
Two-Lane Highways:Basic RelationshipsTwo-Lane Highways:Basic Relationships
Highway Capacity Manual 2000
Example Service Volume Table:Class I Two-Lane Highway
Example Service Volume Table:Class I Two-Lane Highway
Highway Capacity Manual 2000
13: Freeway Concepts13: Freeway Concepts
n Freeway facilities• Basic freeway segments• Freeway weaving• Ramps and ramp junctions• Freeway facilities
n Concepts covered:• Fundamental characteristics• Important parameters• Service volume table
n Freeway facilities• Basic freeway segments• Freeway weaving• Ramps and ramp junctions• Freeway facilities
n Concepts covered:• Fundamental characteristics• Important parameters• Service volume table
Highway Capacity Manual 2000
Basic Freeway SegmentSpeed-Flow RelationshipsBasic Freeway Segment
Speed-Flow Relationships
Highway Capacity Manual 2000
Freeway Facility SegmentsFreeway Facility Segments
Highway Capacity Manual 2000
Freeway Facilities:Traffic Management Strategies
Freeway Facilities:Traffic Management Strategies
n Traffic management processn Freeway management strategies
• Capacity-management strategies• Demand-management strategies
n Performance measures
n Traffic management processn Freeway management strategies
• Capacity-management strategies• Demand-management strategies
n Performance measures
Highway Capacity Manual 2000
14: Transit Concepts14: Transit Concepts
n Introduction and definitionsn Transit facilities discussed:
• Bus– Loading areas– Stops– Busways– Exclusive arterial bus lanes– Mixed-traffic lanes
• Light rail• Street car
n Introduction and definitionsn Transit facilities discussed:
• Bus– Loading areas– Stops– Busways– Exclusive arterial bus lanes– Mixed-traffic lanes
• Light rail• Street car
Highway Capacity Manual 2000
14: Transit Concepts14: Transit Concepts
n Presented discussions:• Basic concepts• General capacity ranges• Priority treatments• Quality-of-service concepts
– Definitions – Performance measures– Quality-of-service factors– Quality-of-service framework
n Presented discussions:• Basic concepts• General capacity ranges• Priority treatments• Quality-of-service concepts
– Definitions – Performance measures– Quality-of-service factors– Quality-of-service framework
Highway Capacity Manual 2000
Relationship Between Person and Vehicle Capacity: Buses
Relationship Between Person and Vehicle Capacity: Buses
Part III: MethodologiesPart III: Methodologies
Part I - IntroductionPart II - ConceptsPart III – MethodologiesPart IV - Corridor and Area-Wide AnalysesPart V - Simulation and Other Models
Highway Capacity Manual 2000
Part III ChaptersPart III Chapters
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
Highway Capacity Manual 2000
Part III ChaptersPart III Chapters
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
Highway Capacity Manual 2000
15: Urban Streets15: Urban Streets
n Changes since 1997 update:• Most major changes were incorporated into
the 1997 update– Intersection delay estimation procedures
• Chapter title has changed:– Arterial Streets Urban Streets
n Changes since 1997 update:• Most major changes were incorporated into
the 1997 update– Intersection delay estimation procedures
• Chapter title has changed:– Arterial Streets Urban Streets
Highway Capacity Manual 2000
15: Urban Streets15: Urban Streets
n Procedure assesses the mobility function of an arterial• Access function is not analyzed, but recognized as an
important considerationn Limitations of the Procedure:
• On-street parking effects• Driveway density• Lane additions/lane drops• Mid-block grades• Mid-block capacity constraints• Mid-block medians/TWLT lane• Turning movements greater than 20% of total volume• Upstream queue effects• Cross-street congestion
n Procedure assesses the mobility function of an arterial• Access function is not analyzed, but recognized as an
important considerationn Limitations of the Procedure:
• On-street parking effects• Driveway density• Lane additions/lane drops• Mid-block grades• Mid-block capacity constraints• Mid-block medians/TWLT lane• Turning movements greater than 20% of total volume• Upstream queue effects• Cross-street congestion
Highway Capacity Manual 2000
Urban Street MethodologyUrban Street Methodology
Highway Capacity Manual 2000
Methodology ChangeMethodology Change
No longer uses “analysis section”…just segments
No longer uses “analysis section”…just segments
Highway Capacity Manual 2000
Sensitivity of Results to Input Variables
Sensitivity of Results to Input Variables
Class I Urban StreetClass I Urban Street
Highway Capacity Manual 2000
Future PlansFuture Plans
n Enhancements• Running time sensitivity to flow rate• Improve sensitivity to filtering and metering
n Next Generation• Include evaluation of access impacts• Provide multimodal LOS
n Enhancements• Running time sensitivity to flow rate• Improve sensitivity to filtering and metering
n Next Generation• Include evaluation of access impacts• Provide multimodal LOS
Highway Capacity Manual 2000
Part III ChaptersPart III Chapters
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
Highway Capacity Manual 2000
Operational methodologyOperational methodology
The basic method remains essentially unchanged from 1997 updateThe basic method remains essentially unchanged from 1997 update
1. Input module
• Geometric conditions • Traffic conditions • Signalization conditions
2. Volume adjustment
• Peak-hour factor • Lane groups • Lane group volumes
4. Capacity analysis
• Lane group capacities • Lane group v/c ratios • Aggregate results
5. Level of service
• Lane group delays • Aggregate delays • Determine LOS
3. Saturation flow rate
• Ideal flow rate • Adjustments
Highway Capacity Manual 2000
1997 Changes to Chapter 91997 Changes to Chapter 9
n Improved Procedure for Actuated Signals
n Improved Delay Equation to Account for:
• Oversaturated Conditions
• Coordinated Operation
n Convert Primary MOE to Control Delay
n Account for Lane Utilization Effects on Saturation Flow Rates
n Change in Approach to Lost Time
n Fix Minor Problems with Permitted Left Turn Model
n Provide Better Guidance for CBD Factor
n Improved Procedure for Actuated Signals
n Improved Delay Equation to Account for:
• Oversaturated Conditions
• Coordinated Operation
n Convert Primary MOE to Control Delay
n Account for Lane Utilization Effects on Saturation Flow Rates
n Change in Approach to Lost Time
n Fix Minor Problems with Permitted Left Turn Model
n Provide Better Guidance for CBD Factor
Highway Capacity Manual 2000
Actuated SignalsActuated Signals
n Improved Procedure for Actuated Signals • Timing plans estimated using actual controller data and
signal design characteristics• Timing plan development is iterative (requires
computer)• Substantial improvements in delay and capacity
estimates for actuated control• Useful to evaluate optimum controller settings
n New Appendix II to estimate average splits• considers effects of initial, extension, maximum,
detector size, detector setback, etc.
n Improved Procedure for Actuated Signals • Timing plans estimated using actual controller data and
signal design characteristics• Timing plan development is iterative (requires
computer)• Substantial improvements in delay and capacity
estimates for actuated control• Useful to evaluate optimum controller settings
n New Appendix II to estimate average splits• considers effects of initial, extension, maximum,
detector size, detector setback, etc.
Highway Capacity Manual 2000
Improved Delay EquationImproved Delay Equation
n Improved Delay Equation• Delay equation to add third term (d3) accounting for
oversaturation• Accounts for varying length of congestion• Refinements for actuated control• Refinements to account for coordinated operation and
effects of upstream signals• Guidance to users on how to collect data in
oversaturated conditions• Multiple time periods• Arrivals vs departures
n Improved Delay Equation• Delay equation to add third term (d3) accounting for
oversaturation• Accounts for varying length of congestion• Refinements for actuated control• Refinements to account for coordinated operation and
effects of upstream signals• Guidance to users on how to collect data in
oversaturated conditions• Multiple time periods• Arrivals vs departures
Highway Capacity Manual 2000
The General Delay ModelThe General Delay Model
d321
dd d++=
average total delay, in seconds/vehicled =d =
d =
d =
uniform vehicle delay component, adjusted for progression quality and for type of signal control(pretimed vs actuated) in seconds/vehicle
residual queue delay component to account for oversaturation queues that may have existed priorto the analysis period
random and oversaturation (incremental) delaycomponent, adjusted for the duration of the peakperiod, the type of signal control, and for upstreamtraffic signal effects, in seconds/vehicle
Where:
1
2
3
Highway Capacity Manual 2000
Oversaturated Time PeriodsOversaturated Time Periods
Analysis of Multiple Time Periods
0
200
400
600
800
1000
1200
1400
1 2 3 4
Time Period
Dem
and
(ve
h/h
r)Analysis of Multiple Time Periods
0
200
400
600
800
1000
1200
1400
1 2 3 4
Time Period
Dem
and
(ve
h/h
r)
Capacity
Highway Capacity Manual 2000
Delay Model ComponentsDelay Model Components
Highway Capacity Manual 2000
LOS Based on Control DelayLOS Based on Control Delay
n Convert Primary MOE to Control Delay• Current HCM procedure estimates Stopped delay by
computing total delay and dividing by 1.3• Remove the 1.3 adjustment• Modify LOS thresholds upward
n Convert Primary MOE to Control Delay• Current HCM procedure estimates Stopped delay by
computing total delay and dividing by 1.3• Remove the 1.3 adjustment• Modify LOS thresholds upward
Subject toChange
1994 1997ABCDEF
< 5< 15< 25< 40< 60> 60
< 6.5< 19.5< 32.5< 52.0< 78.0> 78.0
Highway Capacity Manual 2000
Impact of Using Control DelayImpact of Using Control Delay
n New LOS Thresholds• 1.3 higher than before, rounded up
n New Survey Technique (Appendix III)• time in queue survey, with adjustments
n Consistent with Chapters 10 & 11 and Most Computer Models
Highway Capacity Manual 2000
Lane UtilizationLane Utilization
n Adjust for Lane Utilization Effects• Current HCM allows use of lane utilization
factor to adjust Volumes• Proposed change will not adjust volumes but
rather adjust saturation flow rates to reflect lane utilization effects (no fictitious vehicles)
• More accurate representation result in better estimate of average delay
• Saturation flow rate is better for other models (like TRANSYT and PASSER)
n Adjust for Lane Utilization Effects• Current HCM allows use of lane utilization
factor to adjust Volumes• Proposed change will not adjust volumes but
rather adjust saturation flow rates to reflect lane utilization effects (no fictitious vehicles)
• More accurate representation result in better estimate of average delay
• Saturation flow rate is better for other models (like TRANSYT and PASSER)
Highway Capacity Manual 2000
Computation of saturation flow rateComputation of saturation flow rate
Adjustment factors:
]]]]
N = lanesf = lane widthf = heavy vehiclesf = grade
w
hv
g
]]]]]
f = parkingf = localbusesf = area typef = right turnsf = left turns
p
bb
a
rt
lt
s = s N f f f f f f f f f0 w HV g p bb a LU RT LT
] = lane utilizationflu
Highway Capacity Manual 2000
Lost TimeLost Time
n clarifications (e.g., Y includes all-red)n new variable
• e, extension of effective green into yellown calculate lost time, not input directly
• tL = l1+l2 (as before)
• l2 = Y-e (new calculation)
• g = G+Y-tL (as before)
n new defaults
Highway Capacity Manual 2000
Relationship between actual greenRelationship between actual greenand effective greenand effective green
G
g
Y
r = R + t (effective red time)l
g = G + Y - t (effective green time)l
t ~ Y + ARl
Highway Capacity Manual 2000
CBD FactorsCBD Factors
n Guidance for CBD Factors• Better description of intent of CBD factor
– "Dense Business District"– Narrow sidewalks– Frequent parking– Small radius turns– High bus / taxi activity– High pedestrian volumes
• Should only be used in areas where geometric design and/or other factors (pedestrian, bus activity) significantly increase vehicle headways
n Guidance for CBD Factors• Better description of intent of CBD factor
– "Dense Business District"– Narrow sidewalks– Frequent parking– Small radius turns– High bus / taxi activity– High pedestrian volumes
• Should only be used in areas where geometric design and/or other factors (pedestrian, bus activity) significantly increase vehicle headways
Highway Capacity Manual 2000
HCM 2000 ChangesHCM 2000 Changes
n Re-organized and re-writtenn New queue modeln New ped-bike adjustmentsn New protected-permitted shared LT modeln Other minor changes
n Re-organized and re-writtenn New queue modeln New ped-bike adjustmentsn New protected-permitted shared LT modeln Other minor changes
Highway Capacity Manual 2000
New Queue ModelNew Queue Model
n Back of queuen Accounts for coordinationn Accounts for actuationn Allows over-saturationn Allows initial queue & multi-periodn Predicts various percentile values
n Back of queuen Accounts for coordinationn Accounts for actuationn Allows over-saturationn Allows initial queue & multi-periodn Predicts various percentile values
Highway Capacity Manual 2000
Permitted Left Turn ChangesPermitted Left Turn Changes
n Fix Minor Problems with Permitted Left Turn Model• Estimate of proportion of left turns in the left
lane on multi-lane approach• Adjustments to equation dealing with
boundary conditions (no or very low flow conditions)
n Fix Minor Problems with Permitted Left Turn Model• Estimate of proportion of left turns in the left
lane on multi-lane approach• Adjustments to equation dealing with
boundary conditions (no or very low flow conditions)
Highway Capacity Manual 2000
Part III ChaptersPart III Chapters
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
Highway Capacity Manual 2000
Unsignalized IntersectionsUnsignalized Intersections
n Most changes were incorporated into the 1997 update.• Two way stop controlled• All way stop controlled• Roundabouts
n Most changes were incorporated into the 1997 update.• Two way stop controlled• All way stop controlled• Roundabouts
Highway Capacity Manual 2000
Two-way stop procedure includesTwo-way stop procedure includes
n Revised critical gap parametersn Revised methods for queue length estimatesn Revised control delay estimates
n Revised critical gap parametersn Revised methods for queue length estimatesn Revised control delay estimates
Highway Capacity Manual 2000
Analysis MethodologyAnalysis MethodologyUnsignalized IntersectionsUnsignalized Intersections
SummarizeDemandVolumes
SummarizePhysical
Data
AdjustDemandVolumes
DevelopCritical GapAdjustments
ComputePotentialCapacity
DetermineImpedanceAdjustment
Factor
Evaluate 2-Stage
Gap Acceptance
EvaluateFlared Approach
Effect
ComputeMovementCapacity
EvaluateUpstream
Signal Effects
DetermineLOS
ComputeConflicting
Flows
DetermineProbability of
Queue-Free State
Highway Capacity Manual 2000
1994 HCM capacity equation1994 HCM capacity equation
ttC = 3600 eC = 3600 e
xxff
-Vt-Vt36003600
00(( ))
where:where:
V = conflicting volume (vph)V = conflicting volume (vph)
t = follow-up time (sec)t = follow-up time (sec)
t = critical gap (sec)t = critical gap (sec)
t = t - (t /2)t = t - (t /2)
ff
cc
00 cc ff
Highway Capacity Manual 2000
1997 HCM capacity equation1997 HCM capacity equation
ff
cc
c,yc,y
WhereWhere
tt
tt
VVccp,xp,x
= follow up time (sec)= follow up time (sec)
= critical gap (sec)= critical gap (sec)
= conflicting volume (vph)= conflicting volume (vph)= potential capacity for movement x (pcph)= potential capacity for movement x (pcph)
1 - e1 - e
eeC = VC = Vp,xp,x c,yc,y
36003600VV ttc,yc,y cc
36003600VV ttc,yc,y ff
Highway Capacity Manual 2000
Capacity for gap acceptance method
Capacity for gap acceptance method
Field Capacity, veh/h
ModelCapacityVeh/h
100080060040020000
200
400
600
800
1000
Highway Capacity Manual 2000
Critical Gaps and Follow-up TimesCritical Gaps and Follow-up Timesfor TWSC Intersectionsfor TWSC Intersections
c
f
Highway Capacity Manual 2000
wherewhere
ttc,adjc,adj c,basec,basett
tt
3,LT3,LTttGGc,gc,gtt
c,Tc,TttHVHVPP++ ++ -- --==
= 0.7 sec for movement 7 or 10= 0.7 sec for movement 7 or 10
= Percent grade/100= Percent grade/100
= 0.1 for movements 9, 12; = 0.1 for movements 9, 12; 0.2 for movements 7, 8, 10, and 110.2 for movements 7, 8, 10, and 11
GG
= 1.0 sec for movements 7, 8, 10, and 11= 1.0 sec for movements 7, 8, 10, and 11
= 1.0 sec for 2-lane road; 2.0 sec for 4-lane road= 1.0 sec for 2-lane road; 2.0 sec for 4-lane road
= Percent heavy vehicles in minor movement= Percent heavy vehicles in minor movement
tt c,HVc,HV
c,HVc,HV
PPHVHV
tt c,Gc,G
tt c,Tc,T
tt 3,LT3,LT
Critical Gap Adjustment FactorsCritical Gap Adjustment Factors
Highway Capacity Manual 2000
Follow-up Time Adjustment FactorsFollow-up Time Adjustment Factors
wherewhere
ttf,adjf,adj HVHVf,HVf,HVf,basef,basett tt PP++==
= 0.9 sec for 2-lane road; 1.0 sec for 4-lane road= 0.9 sec for 2-lane road; 1.0 sec for 4-lane road
= Percent heavy vehicles in minor movement= Percent heavy vehicles in minor movement
ttf,HVf,HV
PPHVHV
Highway Capacity Manual 2000
95th percentile queue length estimates
95th percentile queue length estimates
0
50
100
150
200
250
0 0.5 1 1.5
D/C
95th
Que
ue le
ngth
(veh
) C T = 1000
500
100
Highway Capacity Manual 2000
Revised control delay estimatesRevised control delay estimates
n Uses a similar equation to other chapters n Allows for D/C ratios to be greater than 1.0n Allows for any length of analysisn Allows for the acceleration and deceleration
associated with control delay
n Uses a similar equation to other chapters n Allows for D/C ratios to be greater than 1.0n Allows for any length of analysisn Allows for the acceleration and deceleration
associated with control delay
Highway Capacity Manual 2000
Unsignalized Intersection Delay EquationUnsignalized Intersection Delay Equation
Where:Where:
DD22 dd
dd
ss 900T900T450T450Th xh x
x - 1x - 1(( )) x - 1x - 1(( ))++ ++ ++==
s = service times = service time
T = analysis periodT = analysis period
x = degree of utilizationx = degree of utilization
h = departure headwayh = departure headway
55 ++
Highway Capacity Manual 2000
LOS is based on control delayLOS is based on control delay
Level of Service
A < 10 secB > 10 and < 15 secC > 15 and < 25 secD > 25 and < 35 secE > 35 and < 50 secF > 50 sec
Average Control Delayto Minor Street Traffic
Highway Capacity Manual 2000
Two-way stop procedure evaluatesTwo-way stop procedure evaluates
n Pedestrian effectsn Flared minor street approachesn Upstream signal effectsn Two stage gap acceptance processesn Through Traffic impedance effects
n Pedestrian effectsn Flared minor street approachesn Upstream signal effectsn Two stage gap acceptance processesn Through Traffic impedance effects
Highway Capacity Manual 2000
7 98
1: 2, 3, 5, 6, 15, 162: 1, 4,
13, 149, 12
3: 8, 114: 7, 10
1: 2, 3, 5, 152: 4,
13,149
3: 7
1112 10
23
7 9
54
654
123
Cross Intersection
Rank Rank
T-Junction
Traffic Stream PrioritiesTraffic Stream Priorities
16
14
13
15
13
15
14
Highway Capacity Manual 2000
Definition of conflicting volumesDefinition of conflicting volumes
SubjectMovementSubjectMovement
Major StreetLeft Turn
Minor StreetThroughMovement
Minor StreetLeft Turn
V + V + vV + V + v
2V + V + 0.5V + V2V + V + 0.5V + V
+ 2V + V /N + 0.5V + 0.5V + 0.5V +V+ 2V + V /N + 0.5V + 0.5V + 0.5V +V
2V + V + 0.5V + V2V + V + 0.5V + V
V /N + 0.5V + VV /N + 0.5V + V
14
811
912
710
Minor StreetLeft Turn
No. Conflicting Traffic Volumes V
Conflicting Traffic Volume
Part I (near side from left)of 2-state gap acceptance process
Part II (far side from right) of 2-state gap acceptance process
V V
5
2
5
1
1
4
4
2
6
3
I II
6
3
3
6
6
4
1
5
2
6
3
12
9
11
8
L
R
2
2
5
5
3
c,i
O
R
L
S
S
O
+ 2V + V + 0.5V + V+ 2V + V + 0.5V + V1
4
3
6
2
5
S
O
O
S
Highway Capacity Manual 2000
Pedestrian impedancePedestrian impedance
f = (V )(w/s)f = (V )(w/s)36003600
pp
wherewhere
xx
pp
xx
ff
VV
ww
ss
= pedestrian blockage factor= pedestrian blockage factor
= pedestrian walking speed (assumed = pedestrian walking speed (assumed at 4 ft/sec)at 4 ft/sec)
= pedestrian volume (peds/hr and/or = pedestrian volume (peds/hr and/or groups/hr)groups/hr)
= lane width (ft)= lane width (ft)
Highway Capacity Manual 2000
Pedestrians effectsPedestrians effects
05
1015202530354045
0 20 40 60 80 100
Pedestrians per hour
Del
ay (s
)
Highway Capacity Manual 2000
KACTUAL
KACTUAL
CSHARED
CFLARED
CSEPARATE
X
X
KMAX
CA
PA
CIT
Y
QUEUE k
Effect of flared minor approachEffect of flared minor approach
Highway Capacity Manual 2000
Flared minor street approachesFlared minor street approaches
0
5
10
15
20
25
0 1 2 3Flare length (vehs)
Del
ay (s
)
Highway Capacity Manual 2000
Upstream signal parameters include
Upstream signal parameters include
n The distance between intersectionsn Signal timingsn Travel speed on the arterialn Saturation flow rates
n The distance between intersectionsn Signal timingsn Travel speed on the arterialn Saturation flow rates
Highway Capacity Manual 2000
Effect of Upstream SignalsEffect of Upstream Signals
DIS
TAN
CE
TIME
SIGNAL 2
SIGNAL 5
FLOWSPROBABILITY
"SPREAD RATIO" = t /t1
SIGNIFICANT IF D OR D < 1500 FT (500 m)(1/4 mile)
2 5
G2
G5
R2
R5
P1 P3
t2
D2
D5
VP5
VP2N
VNP5
VNP2
t2t5
t5
V2
V5
C2
O2
O5
2 3 41
P2 P4
Highway Capacity Manual 2000
part II
part I
input line
m spaces for passenger cars
V1 V2
V5
The two-stage gap acceptance processThe two-stage gap acceptance process
Highway Capacity Manual 2000
Two-stage gap acceptance processes
Two-stage gap acceptance processes
0
5
10
15
20
25
0 1 2 3
Median storage (vehs)
Del
ay (s
)
Highway Capacity Manual 2000
Shared lane delay to rank 1 movementsShared lane delay to rank 1 movements
1 - p
1 - p
d = rank 1; N > 1
; N = 1
o,j
o,j
dmajor left
*
*
(
(
)
)
VN
( )
dmajor left
V + Vi,1 i,2
i,1
Highway Capacity Manual 2000
Analysis MethodologyAnalysis MethodologyUnsignalized IntersectionsUnsignalized Intersections
SummarizeDemandVolumes
SummarizePhysical
Data
AdjustDemandVolumes
DevelopCritical GapAdjustments
ComputePotentialCapacity
DetermineImpedanceAdjustment
Factor
Evaluate 2-Stage
Gap Acceptance
EvaluateFlared Approach
Effect
ComputeMovementCapacity
EvaluateUpstream
Signal Effects
DetermineLOS
ComputeConflicting
Flows
DetermineProbability of
Queue-Free State
Highway Capacity Manual 2000
The all-way stop procedureThe all-way stop procedure
n Based on the notion that the service time is a function of the conflict type
n The more difficult the conflict - the longer the service time
n Defines “degree-of-conflict” casesn The process is iterative
n Based on the notion that the service time is a function of the conflict type
n The more difficult the conflict - the longer the service time
n Defines “degree-of-conflict” casesn The process is iterative
Highway Capacity Manual 2000
Key Operating ConceptsKey Operating Concepts
AWSC intersections operate in eitherAWSC intersections operate in either2- or 4-phase patterns2- or 4-phase patterns
Vehicle headways depend onVehicle headways depend on
Degree of conflictDegree of conflict
Vehicle typeVehicle type
Turn maneuverTurn maneuver
Intersection geometryIntersection geometry
Highway Capacity Manual 2000
AWSC analysis computational procedureAWSC analysis computational procedure
Input Data
Saturation Headways
Departure Headwaysand Service Time
Capacity andLevel of Service
Highway Capacity Manual 2000
Operating states of AWSC intersectionsOperating states of AWSC intersections
Case 1 Case 2 Case 3
Case 4 Case 5
Highway Capacity Manual 2000
Richardson capacity modelRichardson capacity model
Intersection of one-way streetsIntersection of one-way streets
Intersection of two-way streetsIntersection of two-way streets
Generalized model for single lane sitesGeneralized model for single lane sites
Generalized model for multi-lane sitesGeneralized model for multi-lane sites
Highway Capacity Manual 2000
Departure headway Departure headway
n The mean departure headway is a function of probability of the “degree-of-conflict” case and the departure headway (or service time).
n The probabilities are themselves a function of the departure headways.
n The mean departure headway is a function of probability of the “degree-of-conflict” case and the departure headway (or service time).
n The probabilities are themselves a function of the departure headways.
Highway Capacity Manual 2000
Intersection of one-way streetsIntersection of one-way streets
Where:
s = service time with no vehicle on conflicting approach
= arrival rate
s = service time with vehicle on conflicting approach
s = mean service time for northbound approach
1
2
i
N
SubjectApproach
ConflictingApproachs =
s 1 - (s + s )1 1N 2
1 - (s + s )1 12
N W 22
Highway Capacity Manual 2000
Capacity and delayCapacity and delay
n The capacity is evaluated by increasing the traffic demand on the subject approach until the degree of utilization is equal to 1.0.
n The delay is evaluated using a non steady state equation similar to the one used in the TWSC section and in other chapters.
n The capacity is evaluated by increasing the traffic demand on the subject approach until the degree of utilization is equal to 1.0.
n The delay is evaluated using a non steady state equation similar to the one used in the TWSC section and in other chapters.
Highway Capacity Manual 2000
Emergence of Roundabouts in the U.S.A.Emergence of Roundabouts in the U.S.A.
n Interest first appeared in early 1990’sn Maryland and Florida produced first guidesn Most states now show an active interestn FHWA has released a national guide
n Interest first appeared in early 1990’sn Maryland and Florida produced first guidesn Most states now show an active interestn FHWA has released a national guide
Highway Capacity Manual 2000
Methods of evaluating roundaboutsMethods of evaluating roundabouts
AnalyticalAnalyticalCritical gap, follow-up timeCritical gap, follow-up timeSIDRA (Australian)SIDRA (Australian)
EmpiricalEmpiricalRegression function based on geometricRegression function based on geometricfeaturesfeaturesARCADY, RODEL (British)ARCADY, RODEL (British)
SimulationSimulationMicroscopic modeling of roundaboutsMicroscopic modeling of roundaboutsCORSIM, Integration, ParamicsCORSIM, Integration, Paramics
Highway Capacity Manual 2000
Injury accident reductionsInjury accident reductions
Britain 35%35%
36%36%
38%38%
55%55%
74%74%
75%75%
78%78%
51%51%
Denmark
Switzerland
The Netherlands
Norway
Australia
France
United StatesUnited States
Source: Maryland Department of Transportation; NCHRP synthesis
Highway Capacity Manual 2000
Roundabout procedureRoundabout procedure
n Based on a gap acceptance approachn Evaluated on limited US field experiencen Provides two estimates of capacity and offers
no advice on delays• FHWA Guide offers additional information on:
– Capacity estimation (single and double-lane)– Delay estimation
n Based on a gap acceptance approachn Evaluated on limited US field experiencen Provides two estimates of capacity and offers
no advice on delays• FHWA Guide offers additional information on:
– Capacity estimation (single and double-lane)– Delay estimation
Highway Capacity Manual 2000
Comparison with othersComparison with others
UK
Australia (Troutbeck)
Suggestedrelationship(exponential)
Circulating Flow (veh/h)
Entrycapacity(veh/h)
12001000800600400200200
400
600
800
1000
1200
German
Highway Capacity Manual 2000
Comparison with othersComparison with others
EntryCapacity(veh/h)
12001000800600400200200
400
600
800
1000
1200
Australia(Troutbeck)
Suggestedlower-boundrelationship
Circulating Flow (veh/h)
German
Increased criticalgap parameters
Highway Capacity Manual 2000
Roundabout evaluationRoundabout evaluation
n Suggest that the upper-bound is more appropriate for most roundabouts.
n Use the lower bound estimate when the speeds are particularly low and if roundabouts are not common.
n Suggest that the upper-bound is more appropriate for most roundabouts.
n Use the lower bound estimate when the speeds are particularly low and if roundabouts are not common.
Highway Capacity Manual 2000
Single-Lane RoundaboutsSingle-Lane Roundabouts
0
200
400
600
800
1000
1200
1400
0 400 800 1200 1600 2000 2400Circulatory Flow (veh/h)
Max
imum
Ent
ry F
low
(veh
/h)
Urban & Rural Single-Lane Roundabouts
Urban Compact Roundabouts
Entering and circulating flow = 1800 veh/h
Highway Capacity Manual 2000
Double-Lane RoundaboutsDouble-Lane Roundabouts
0
400
800
1200
1600
2000
2400
2800
0 400 800 1200 1600 2000 2400 2800 3200 3600
Circulatory Flow (veh/h)
Max
imu
m E
ntr
y F
low
(ve
h/h
)
Highway Capacity Manual 2000
Capacity AdjustmentsCapacity Adjustments
n Short lanes (flared approaches)
n Pedestrians
n Short lanes (flared approaches)
n Pedestrians
Highway Capacity Manual 2000
Capacity adjustments: Short lanesCapacity adjustments: Short lanes
No. of vehicle spaces in short lane
Capacity factor (applied to double-lane approach capacity)
0 (single-lane approach) 0.500 1 0.707 2 0.794 4 0.871 6 0.906 8 0.926
10 0.939
n Short lanes are the additional partial lanes added when flaring a roundabout from one to two lanes
n Short lanes are the additional partial lanes added when flaring a roundabout from one to two lanes
Highway Capacity Manual 2000
Capacity adjustment: Pedestrians at single-lane roundabout
Capacity adjustment: Pedestrians at single-lane roundabout
0.70
0.75
0.80
0.85
0.90
0.95
1.00
0 100 200 300 400 500 600 700 800 900
100 ped/h
200 ped/h
300 ped/h
400 ped/h
circular flow rate qk [pcu/h]
Reduction factor M [-]
Highway Capacity Manual 2000
Capacity adjustment: Pedestrians at double-lane roundabout
Capacity adjustment: Pedestrians at double-lane roundabout
0.70
0.75
0.80
0.85
0.90
0.95
1.00
0 200 400 600 800 1000 1200 1400
100 ped/h
200 ped/h300 ped/h
400 ped/h
Reduction factor M [-]
circular flow rate qk [pcu/h]
Highway Capacity Manual 2000
DelayDelay
n Control delay• Includes initial deceleration delay, queue
move-up time, stopped delay, and final acceleration delay
n Geometric delay• Delay experienced by a single vehicle with no
conflicting flows• Caused by geometric features
n Total delay = Control + Geometricn Typical measure used: control delay
n Control delay• Includes initial deceleration delay, queue
move-up time, stopped delay, and final acceleration delay
n Geometric delay• Delay experienced by a single vehicle with no
conflicting flows• Caused by geometric features
n Total delay = Control + Geometricn Typical measure used: control delay
Highway Capacity Manual 2000
DelayDelay
0
10
20
30
40
50
60
0 400 800 1200 1600 2000 2400
Entering flow (veh/h)
Del
ay (
s)
400 veh/h 800 veh/h 1200 veh/h 1600 veh/h 2000 veh/h 2400 veh/hCapacity
T=0.25 hT=0.25 h
800
1200
400 1600
2000
2400
Highway Capacity Manual 2000
Queue EstimationQueue Estimation
n Average queue (50th percentile)• Equivalent to vehicle-hours of delay per hour
on an approach• Useful for comparing performance with other
intersection formsn Maximum queue (95th percentile)
• Used for design purposes• Most common queue parameter
n Average queue (50th percentile)• Equivalent to vehicle-hours of delay per hour
on an approach• Useful for comparing performance with other
intersection formsn Maximum queue (95th percentile)
• Used for design purposes• Most common queue parameter
Highway Capacity Manual 2000
50th Percentile (Average) Queue Estimation
50th Percentile (Average) Queue Estimation
Little’s rule:L = v * d / 3600
where:L = queue length, vehv = entry flow, veh/hd = average delay, s/veh
Little’s rule:L = v * d / 3600
where:L = queue length, vehv = entry flow, veh/hd = average delay, s/veh
Highway Capacity Manual 2000
95th Percentile Queue Estimation95th Percentile Queue Estimation
0 0.2 0.4 0.6 0.8 1.0 1.2 1.41
2
3
4
5678910
20
30
40
5060708090100
∞
Exp
ecte
d M
axim
um N
umbe
r of
Veh
icle
s in
Que
ue, Q
95
[veh
]
v/c Ratio [-]
Highway Capacity Manual 2000
Highway Capacity Committee’s web siteHighway Capacity Committee’s web site
HCM User’s web site (maintained by FHWA)HCM User’s web site (maintained by FHWA)
HCM Web SitesHCM Web Sites
http://traffic.ce.gatech.edu/hcqs
http://www.hcmweb.net
http://www-mctrans.ce.ufl.edu/info-cen/hcs/hcs.htm
HCS software siteHCS software site
Highway Capacity Manual 2000
+ = HCM2000
BOOKCD-ROM
.pdf files
Multimedia version
tutorials
examples
audio explanations
video clips
hypertext/search
software link
3rd party software
Highway Capacity Manual 2000
Part III ChaptersPart III Chapters
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
15: Urban Streets (30)16: Signalized Intersections (174)17: Unsignalized Intersections (118)18: Pedestrians (34)19: Bicycles (26)20: Two-Lane Highways (52)21: Multilane Highways (32)22: Freeway Facilities (64)23: Basic Freeway Segments (32)24: Freeway Weaving (40)25: Ramps and Ramp Junctions (42)26: Interchange Ramp Terminals (18)27: Transit (46)
Highway Capacity Manual 2000
27: Transit Analysis27: Transit Analysis
n Chapter is summary of Transit Capacity and Quality of Service Manual.
n Capacity and LOS estimates are provided• Bus• LRT
n Chapter is summary of Transit Capacity and Quality of Service Manual.
n Capacity and LOS estimates are provided• Bus• LRT
Highway Capacity Manual 2000
Typical Busway Line-Haul Passenger Volumes
Typical Busway Line-Haul Passenger Volumes
Highway Capacity Manual 2000
Average Bus Speed in a Freeway HOV Lane
Average Bus Speed in a Freeway HOV Lane
Highway Capacity Manual 2000
Base Bus Running Time (min/mi)
Base Bus Running Time (min/mi)
Highway Capacity Manual 2000
Bus Running Time LossesBus Running Time Losses
Highway Capacity Manual 2000
Skip-Stop Speed Adjustment Factor
Skip-Stop Speed Adjustment Factor
Highway Capacity Manual 2000
Bus Lane Volumes and SpeedsBus Lane Volumes and Speeds
Highway Capacity Manual 2000
Factors Influencing Transit Capacity and Speed
Factors Influencing Transit Capacity and Speed
Highway Capacity Manual 2000
Transit LOS AnalysisTransit LOS Analysis
n Quality of service is computed at three different levels of aggregation:• Transit Stop• Transit Route• Transit System
n Quality of service is computed at three different levels of aggregation:• Transit Stop• Transit Route• Transit System
Highway Capacity Manual 2000
Transit LOS AnalysisTransit LOS Analysis
n Six Quality of Service Criteria are identified at each level of aggregation.• Service Frequency• Hours of Transit Service• Passenger Load• Reliability• Service Coverage• Ratio of Transit to Auto Travel Times
n Six Quality of Service Criteria are identified at each level of aggregation.• Service Frequency• Hours of Transit Service• Passenger Load• Reliability• Service Coverage• Ratio of Transit to Auto Travel Times
Highway Capacity Manual 2000
Transit LOS AssessmentTransit LOS Assessment
n Service Frequencyn Service Frequency
Highway Capacity Manual 2000
Transit LOS AssessmentTransit LOS Assessment
n Hours of Servicen Hours of Service
Highway Capacity Manual 2000
Transit LOS AssessmentTransit LOS Assessment
n Passenger Loadn Passenger Load
Highway Capacity Manual 2000
Transit LOS AssessmentTransit LOS Assessment
n Bus Service Reliabilityn Bus Service Reliability
Highway Capacity Manual 2000
Transit LOS AssessmentTransit LOS Assessment
n Ratio of Auto to Bus Travel Tiimen Ratio of Auto to Bus Travel Tiime
Highway Capacity Manual 2000
Transit AnalysisTransit Analysis
n Additional performance measures can be computed• Bus & rail stop dwell time.• Bus & rail stop capacity• Mean bus speed
– freeway HOV lanes.–urban street bus lanes.–Mixed flow lanes
• Mean rail speed• Vehicle and person capacity of bus lanes.
n Additional performance measures can be computed• Bus & rail stop dwell time.• Bus & rail stop capacity• Mean bus speed
– freeway HOV lanes.–urban street bus lanes.–Mixed flow lanes
• Mean rail speed• Vehicle and person capacity of bus lanes.
Parts IV and V: Corridor and Area-Wide Analyses and Simulation
Parts IV and V: Corridor and Area-Wide Analyses and Simulation
Part I - IntroductionPart II - ConceptsPart III – MethodologiesPart IV - Corridor and Area-Wide AnalysesPart V - Simulation and Other Models
Highway Capacity Manual 2000
Part IV & V ChaptersPart IV & V Chapters
n 28: Assessment of Multiple Facilities (6)n 29: Corridor Analysis (33)n 30: Areawide Analysis (39)n 31: Simulation and Other Models (37)
n 28: Assessment of Multiple Facilities (6)n 29: Corridor Analysis (33)n 30: Areawide Analysis (39)n 31: Simulation and Other Models (37)
Highway Capacity Manual 2000
Parts IV and V:Purpose and Content
Parts IV and V:Purpose and Content
n To provide guidance on the use and adaptation of HCM procedures for corridor and area-wide analyses
n To provide guidance on the use and adaptation of HCM procedures for corridor and area-wide analyses
Highway Capacity Manual 2000
28: Assessment of Multiple Facilities28: Assessment of Multiple Facilities
n System analysis framework• Roadway structure (points, segments,
facilities, corridors, area-wide)• Facility types (arterial, freeway, rural
highway)
n System analysis framework• Roadway structure (points, segments,
facilities, corridors, area-wide)• Facility types (arterial, freeway, rural
highway)
Facility
Corridor
Areawide
Point
Segment
Highway Capacity Manual 2000
n Six Measures of System Performance
• Quantity of congestion• Intensity of congestion• Duration of congestion• Extent of congestion• Variability• Accessibility
n System Performance Report Card• Modal LOS Report Card (A/C/A/D)
n Six Measures of System Performance
• Quantity of congestion• Intensity of congestion• Duration of congestion• Extent of congestion• Variability• Accessibility
n System Performance Report Card• Modal LOS Report Card (A/C/A/D)
28: Assessment of Multiple Facilities28: Assessment of Multiple Facilities
Highway Capacity Manual 2000
System Performance Evaluation:“Report Card” Approach
System Performance Evaluation:“Report Card” Approach
Highway Capacity Manual 2000
29: Corridor Analysis29: Corridor Analysis
Highway Capacity Manual 2000
29: Corridor Analysis29: Corridor Analysis
n Guidance on the Application of Part III Chapters to Corridor Analysis
n Highway Corridor Methodology• Compute segment capacity• Adjust temporal demand for Bottlenecks• Compute free flow speed• Compute actual speed• Compute queue delay• Compute performance measures
n Transit/Highway Corridors
n Guidance on the Application of Part III Chapters to Corridor Analysis
n Highway Corridor Methodology• Compute segment capacity• Adjust temporal demand for Bottlenecks• Compute free flow speed• Compute actual speed• Compute queue delay• Compute performance measures
n Transit/Highway Corridors
Highway Capacity Manual 2000
30: Area-wide Analysis30: Area-wide Analysis
n Extension of the HCM to Regional Planning Models
n Highway Facilities Methodology• Determine free flow speed• Determine link capacity• Determine link speed• Determine performance measures
n Transit Facilities Methodologyn Example Problems
n Extension of the HCM to Regional Planning Models
n Highway Facilities Methodology• Determine free flow speed• Determine link capacity• Determine link speed• Determine performance measures
n Transit Facilities Methodologyn Example Problems
Highway Capacity Manual 2000
Determination of Link SpeedDetermination of Link Speed
Highway Capacity Manual 2000
31: Simulation and Other Models31: Simulation and Other Models
Typology of ModelsTypology of Models
Highway Capacity Manual 2000
n Strengths of simulation models• Treats variations in time and space• Considers interactions of queues
n Shortcomings of simulation models• Requires considerable input• Requires verification, calibration, and
validation• Can provide misleading results to users
who are not sufficiently familiar with the base assumptions and processes
n Strengths of simulation models• Treats variations in time and space• Considers interactions of queues
n Shortcomings of simulation models• Requires considerable input• Requires verification, calibration, and
validation• Can provide misleading results to users
who are not sufficiently familiar with the base assumptions and processes
31: Simulation and Other Models31: Simulation and Other Models
Highway Capacity Manual 2000
n Simulation Model Descriptors• Stochastic vs. Deterministic Models• Event Based vs. Time Based Models• Micro, Meso, Macro Models• Static Flow vs. Time Varying Models• Descriptive vs. Optimization Models
n Examples
n Simulation Model Descriptors• Stochastic vs. Deterministic Models• Event Based vs. Time Based Models• Micro, Meso, Macro Models• Static Flow vs. Time Varying Models• Descriptive vs. Optimization Models
n Examples
31: Simulation and Other Models31: Simulation and Other Models
Highway Capacity Manual 2000
n Selecting a Model• Determining Project Scope• Assessing HCM Methodologies• Selecting a Model
– Model Capabilities– Data Availability– Ease of Use– Past Performance– Validation/Calibration
n Selecting a Model• Determining Project Scope• Assessing HCM Methodologies• Selecting a Model
– Model Capabilities– Data Availability– Ease of Use– Past Performance– Validation/Calibration
31: Simulation and Other Models31: Simulation and Other Models
Highway Capacity Manual 2000
Performance Measures for Uninterrupted Flow FacilitiesPerformance Measures for
Uninterrupted Flow Facilities