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Overview of 2010 HCM
Mark Vandehey
Jim Schoen
November 18, 2010
Highway Capacity Manual
• Widely accepted in the U.S. and internationally
• Managed by the Transportation Research Board (TRB) Committee
on Highway Capacity and Quality of Service
• Supporting research comes from a variety of sources
– National Cooperative Highway Research Program (NCHRP)
– Federal Highway Administration
– State Department of Transportation (DOT) research
– International research
– Others
• 2010 Edition is 5th major revision (1950, 1965, 1985, 2000)
NCHRP 3-92 – Production of the 2010 HCM
• Project began in October 2007
• Final 2010 HCM Delivered to TRB in January 2010 (pending final
coordination needs)
• Scheduled for publication by TRB by the end of 2010
• Key tasks:
State of the Art Review and Inventory
Focus Group Survey
Supplemental Research for 2010 HCM
Prepare Draft Chapters
Assist TRB During Publication Process
Summary of Significant Changes
• Incorporation of New Research
• Integrated Multimodal Approach
• Increased Emphasis of Alternative Tools
• New Chapter on Active Traffic Management
Incorporation of New Research
• NCHRP 3-60 (Interchange Ramp Terminals)
• NCHRP 3-64 (HCM Applications Guide)
• NCHRP 3-65 (Roundabouts in the United States)
• NCHRP 3-70 (Multi-Modal Arterial Level of Service)
• NCHRP 3-75 (Analysis of Freeway Weaving)
• NCHRP 3-79 (Predicting Travel Speeds for Urban Streets)
• NCHRP 3-82 (Default Values for HCM)
• NCHRP 3-85 (Guidelines for the Use of Alternative Traffic Analysis Tools)
• NCHRP 20-7 (Two-lane Highways)
• FHWA Research on Active Traffic Management
• NCHRP 3-92
• Signalized Intersection Methodology (New Delay Method and Structure Changes reflecting Actuated Control)
• Gap Acceptance for Six-Lane, Two-Way Stop Controlled Intersections
• 75 Mph Speed Flow Curve for Freeways
More Emphasis on Alternative Tools
• Explicit recognition that HCM analytical procedures may not always
be the best procedure
• Range of alternative tools
– Deterministic tools (e.g., TRANSYT-7F for arterial performance)
– Stochastic tools (e.g., VISSIM for network performance)
• Examples of applications
Alternative Tool Example: Backup from Signal
Mainline vehicles unable to reach the exit lanes
Wasted time on the signal approach
Active Traffic Management
• New ATM Chapter
– Describes ATM measures
– Provides known information/methods for evaluating impacts on freeway capacity and performance.
– Strategies for maximizing return on investment
– Advises on appropriateness of HCM and simulation methods of analysis and any special considerations.
– Managed lanes (HOV/HOT), Congestion Pricing, etc.
– Innovative Operations, Innovative Designs
Lane and Shoulder Treatments
FHWA
Managed Lanes Primer
Google Street View
Congestion Pricing
FHWA, MinnDOT
Technologies that Complement Congestion Pricing Primer
Congestion Pricing Primer
Innovative Interchange Designs
High Capacity Intersection Designs
HCM Evolution
• HCM scope has grown over time
– Increasing coverage of various system elements and modes
– User interest in more-detailed procedures
• HCM page count has grown correspondingly
– 1950: 160 pages
– 1965: 432 pages
– 1985: 512 pages
– 2000: 1,224 pages
Overall Organization
• The 2010 HCM will consist of four volumes
– Volume 1: Concepts
– Volume 2: Uninterrupted Flow
– Volume 3: Interrupted Flow
– Volume 4: Applications Guide
Volume 4
• Electronic-only
• Four main elements
– Methodological details
– Interpretations
– Technical reference library
– HCM applications guide
Methodological Details
• Supplemental chapters (24–34)
– Technical details
– Alternative tool applications
– Extra sample problems
• Emerging topics chapters
– Chapter 35, Active Traffic Management
• Ability to add new material between major HCM updates
Interpretations
• Interpretations
• Clarifications
• Errata
Technical Reference Library
• Source research
• Electronic copies of many references
• Computational engines
Applications Guide
• Examples of applying HCM to real-world problems
• Focus on process, rather than computational steps
• Case studies 1–5 available at hcmguide.com
• New case study 6 on simulation application
Interrupted Flow Chapters
– Urban Street Facilities
• Urban Street Segments
• Signalized Intersections
• Two-way Stop-Controlled Intersections
• All-way Stop-Controlled Intersections
• Roundabouts
• Interchange Ramp Terminals
– Exclusive Pedestrian and Bicycle Facilities
FDOT Quality/LOS Handbook 2002
Chapter 16
Urban Street Facilities
• Scope
– Facility (= two or more segments)
• 0.75 to 2.0 miles long in urbanized downtown areas
• 1.5 to 5.0 miles long in other areas
– Separate methodology for auto, ped, bike, and transit modes
– Emphasizes combined evaluation of auto, ped, bike, and transit
• Methodology
– Aggregates key segment performance measures
• Example Problems
– Demonstrate integrated multimodal evaluation process
Chapter 17
Urban Street Segments
• Scope
– Segment (= link + boundary intersections)
– Signal, TWSC, AWSC, or roundabout boundary intersections
– Models signal coordination
– Separate methodology for auto, ped, bike, and transit modes
Chapter 18
Signalized Intersections
• Scope
– Isolated signalized intersection
– Separate methodology for auto, ped, and bike modes
• A Closer Look
– Automobile Methodology
Chapter 18
Signalized Intersections
• Automobile Methodology
– Actuated phase duration prediction
• Controller operation inputs
– Simultaneous gap-out
– Flashing-yellow-arrow operation
• Controller phase inputs
– Passage time
– Minimum green
– Recall
– Dual entry
• Detector design
– Detector length
• Based on HCM 2000 Chapter 16 -Appendix B
X
Chapter 18
Signalized Intersections
• Automobile Methodology
– Performance measures
• Automobile control delay
• Queue storage ratio
– Percentile queue procedure
• Volume-to-capacity (v/c) ratio
• Level of service is based on control delay and v/c ratio
Chapter 19
Two-Way Stop-Controlled Intersections
• Gap acceptance parameters for six-lane streets added
• Interface with urban street segment methodology for upstream signal effects
• Analysis of major street U-turns on 4-lane and 6-lane streets
• Improved analysis of shared/short lanes
• Updated procedure for analyzing unsignalized pedestrian crossings
Chapter 20
All-Way Stop-Controlled Intersections
• Restructure of chapter to make procedure clearer
• Explicit incorporation of details to calculate AWSC with three-lane approaches (details in Volume 4)
• Queuing model added
Ph
oto
: L
ee R
od
egerd
ts
Chapter 21
Roundabouts
• Incorporates NCHRP Report 572 methodologies (with enhancements and extensions)
• Lane-by-lane analysis of multilane roundabouts
Ph
oto
: C
ase
y B
erg
h
Chapter 21
Roundabouts (cont.)
• LOS table for roundabouts
– Consistent with TWSC and AWSC due to similar delay formulation and lack of guaranteed service (unlike signals)
– Recognized need for additional research
Level of Service by Volume-to-Capacity Ratio* Control Delay (s/veh) v/c ≤ 1.0 v/c >1.0
0 – 10 A F >10 – 15 B F >15 – 25 C F >25 – 35 D F >35 – 50 E F
>50 F F
1
Chapter 22
Interchange Ramp Terminals
• Scope
– Operational evaluation of signalized ramp-crossroad Intersection
– Quick estimation method for interchange type selection
– Methodology addresses auto mode only
• Methodology
– Signalized intersection methodology in Chapter 18
– Roundabout methodology in Chapter 22
• Elements
– Additional saturation flow rate factors • Lane utilization factor
• Traffic pressure factor
• Turn radius factor
– Additional lost time procedure
Volume 2:
Uninterrupted Flow
• CH 10: Freeway Facilities
• CH 11: Basic Freeway Segments
• CH 12: Freeway Weaving Segments
• CH 13: Freeway Merging and Diverging
• Segments
• CH 14: Multilane Highways
• CH 15: Two-Lane Highways
Ch: 10 Freeway Facilities
• Macroscopic Method by Segment
– Basic Freeway Segments
– Weaving Segments
– On-ramp and Off-Ramp Segments
• Directional Methodology
• Extended Time-Space Domain
– Distinguish Demand and Volume
– Queue Interaction between segments and time periods
• Two Flow Regimes
– Undersaturated (all d/c<1.0)
– Oversaturated (any d/c>1.0)
• Implemented in FREEVAL2010
CH 11: BASIC FREEWAY SEGMENTS
• New Speed – Flow Curves → New MSF Values
• New algorithm and process for estimating FFS
• Recommended Default Values
New Speed-Flow Curves:
CH 12: FREEWAY WEAVING SEGMENTS
• New ways to consider length, width, and configuration.
• New speed-prediction algorithms.
• New approach to weaving capacity.
CH 13: FREEWAY MERGING AND DIVERGING
SEGMENTS
• No significant changes to HCM 2000.
• “Reasonableness Check” added to initial predictions of flow in Lanes 1 and 2.
• Two minor changes in predictive equations for v12 to avoid discrepancies in extreme cases.
CH 14: MULTILANE HIGHWAYS
• No major changes in base methodology.
• Like basic freeway segments, no interpolation between free flow curves.
• Added analysis procedure for bicycles on multilane highways.
CH 15: TWO-LANE HIGHWAYS
• Two-way analysis methodology deleted.
• Some basic characteristic curves and tables were revised and updated.
• Third class of two-lane highway added as an alternative procedure: Two-Lane Highways in Built-Up Areas. FDOT procedure used.
• Procedure added for bicycles
on two-lane highways.
Multimodal LOS Measure Issues
• Current pedestrian & bicycle measures generally reflect a traffic engineer’s perspective
– Speed, delay, space
– Florida & NCHRP 3-70 research suggest these aren’t the key factors
– Auto volumes highly important to bike & ped service quality
• Transit measures reflect the passenger perspective, but four individual
measures can be difficult to apply
HCM2000: Ped LOS A HCM2000: Ped LOS D
HCM Focus Group Findings
• Many jurisdictions don’t require multimodal analyses
– Therefore, most often they aren’t performed
• Jurisdictions that do want to perform pedestrian & bicycle analyses don’t find the current HCM measures useful
– For example, Maryland & Florida use measures of user comfort
• Most pedestrian and bicycle facilities don’t have capacity or speed issues
– No need to analyze them using HCM procedures
2010 HCM Approach
• Focus on the traveler perspective
• Allow trade-offs between modes to be evaluated
– Presence of one mode affects the service quality of the other modes
Mode Affected
Impacting Mode
Auto Ped Bike Transit
Auto Auto & HV volumes Turning patterns
Lane configurations
Minimum green time
Turn conflicts Mid-block xings
Turn conflicts
Passing delay
Heavy vehicle
Blocking delay: stops
Signal priority
Ped
Auto & HV volumes Cycle length
Driver yielding Turn conflicts
Traffic separation
Sidewalk crowding Crosswalk crowding
Cross-flows
Shared-path conflicts
Bicyclist yielding
Heavy vehicle
Transit stop queues
Stop cross-flows Vehicle yielding
Bike
Auto & HV volumes
Auto & HV speed
On-street parking
Turn conflicts
Traffic separation
Shared-path conflicts
Min. green time
Turn conflicts Mid-block xings
Bike volumes
Heavy vehicle
Blocking delay: stops Tracks
Transit Auto volumes
Signal timing
Ped. env. quality Minimum green
time
Turn conflicts
Mid-block xings
Bike env. quality
Bike volumes Bus volumes
Service Measures in the 2010 HCM
System Element
Service Measure Provided
Chapter Auto Ped Bike Transit
Freeway Facility 10
Basic Freeway Segment 11
Freeway Weaving Segment 12
Fwy. Merge/Diverge Seg. 13
Multilane Highway 14
Two-Lane Highway 15
Urban Street Facility 16
Urban Street Segment 17
Signalized Intersection 18
Two-Way Stop 19
All-Way Stop 20
Roundabout 21
Interchange Ramp Term. 22
Off-Street Ped-Bike Facility 23
LOS at Unsignalized Crossings
• Estimates pedestrian delay
• Allows consideration of different crossing treatments
• Based on 4 factors
– Traffic volume - # of lanes crossed
– Crossing distance - Motorist yield rate
Example:
2-lane arterial with marked crosswalk, but nobody is yielding…
Inputs: 1,000 peak-hour vehicles
2 lanes crossed
30 feet crossing distance
10% yield rate
Output: Average delay = 44 seconds
Ped LOS = E
LOS at Unsignalized Crossings
Example (cont.):
Install rapid-flash beacons to improve driver compliance…
Inputs: 1,000 peak-hour vehicles
2 lanes crossed
30 feet crossing distance
80% yield rate
Output: Average delay = 6 seconds
Ped LOS = B
45
Multimodal LOS Defined for Urban Streets
• MMLOS measures the degree to which the urban street design and operations meets the needs of each mode’s users
• Four level of service results for the street:
–Auto, Transit, Bicycle, Pedestrian
• A combined LOS is not calculated
Main Street Level of Service
User Type AM Pk Hr PM Pk Hr
Auto C E
Transit B C
Bicycle D C
Pedestrian C D
46
MMLOS Urban Street Applications
• Segments
– All four modes
• Signalized Intersections
– Auto, ped and bike mode
• Facility
– All four modes
segment facility
47
Pedestrian LOS: Urban Street Segments
• Factors include:
– Outside travel lane width (+)
– Bicycle lane/shoulder width (+)
– Buffer presence (e.g., on-street parking, street trees) (+)
– Sidewalk presence and width (+)
– Volume and speed of motor vehicle traffic in outside lane (-)
Pedestrian density considered separately
Worse of density LOS/ segment LOS used to determine LOS
48
Pedestrian LOS: Signalized Intersections
• Factors include:
– Permitted left turn and right-turn-on-red volumes (-)
– Cross-street motor vehicle volumes and speeds (-)
– Crossing length (-)
– Average pedestrian delay (-)
– Right-turn channelizing island presence (+)
49
Bicycle LOS: Urban Street Segments
• Factors include:
– Volume and speed of traffic in outside travel lane (-)
– Heavy vehicle percentage (-)
– Pavement condition (+)
– Bicycle lane presence (+)
– Bicycle lane, shoulder, and outside lane widths (+)
– On-street parking presence and utilization (+/-)
50
Bicycle LOS: Signalized Intersections
• Factors included:
– Width of outside through lane and bicycle lane (+)
– Cross-street width (-)
– Motor vehicle traffic volume in the outside lane (-)
51
Transit LOS: Urban Street Segments
• Factors include:
– Service frequency (+)
– Average bus speed (+)
– Bus reliability (+)
– Average passenger load (-)
– Shelter, bench presence (+)
– Pedestrian LOS score for segment (+)
”Transit” covers buses, streetcars, street-running light rail
52
Auto LOS: Urban Street Segments
• Traveler perception model factors include:
– Number of stops
– Left-turn lane presence
Perception model had the best fit to the data, but testing around the US found an agency preference for current speed-based LOS
2010 HCM will present both measures
Auto LOS to be based on average travel speed
NCHRP 3-70 performance measure will also be provided
Urban Street Facilities: Ped/Bike/Transit LOS
• Average segment LOS score, weighted by
segment length
• Average signalized intersection LOS score
• Segment and intersection LOS combined and
weighted to generate facility LOS
Urban Street Facilities: Auto LOS
• Factors included in NCHRP 3-70 model:
– Average segment auto LOS score, weighted
by segment length
• Traffic signal effects included in stops per mile input to the
segment score
• LOS to be based on average travel speed for the
facility
Traditional Data Needs
• Typical Transportation Analysis Data Collection Efforts
– Peak Hour Traffic Counts • Passenger Vehicles
• Pedestrians
• Bicycles
• Heavy Vehicles
– Roadway Inventory • Sidewalks
• Bicycle Lanes
• Transit Stops/Amenities
• Transit Schedule
• Posted Roadway Speed
• Roadway Cross-Section
• Median Treatment
• Illumination
– Signalized Intersection Data • Signal Timing Sheets
• Signal Phasing
• Right-turn on Red
Source: Bing Maps
Additional Data Needs
• Additional MMLOS Data Collection
– Weekday PM Peak Hour Traffic
Counts • Number of Vehicles by Lane
– Roadway Inventory
• Length of Roadway Segment
• Roadway Cross-Section Dimensions
• Number of Trees/Bushes (in curb tight
landscape strip)
• Percent Occupancy of On-street Parking
• Pavement Condition Rating
• Jaywalking Occurrences
• Number of Driveways within Segment
– Transit Inventory • Bus Occupancy
• Transit Reliability
• Average Trip Length
Source: Google Maps
Data Forms: Segment Data
Data Forms: Roadway Cross-Section
Data Forms: Traffic Data
Data Forms: Transit Data
Analysis Results: Existing SW 185th Avenue Section
• Evergreen to Cornell (2 segments)
• Cornell to Walker (3 segments)
Analysis Results: Existing SW 185th Avenue Section
Note: HCM Auto LOS
would be LOS F based on
corridor average travel
speed of 11 mph.
Examples and Sensitivity
• Pedestrian Facilities
• Bicycle Facilities
• Transit Facilities
• Travel Lanes
Example: Enhancing Pedestrian Facilities
• Existing
• Widen ROW for landscape strip
• Existing
• Provide landscape strip, 10-foot sidewalks, and on-street parking
Increased ROW
Street Score LOS
Auto 2.77 C
Transit 2.56 B
Bike 3.43 C
Ped 3.37 C
Street Score LOS
Auto 2.77 C
Transit 2.53 B
Bike 3.22 C
Ped 3.17 C
Ped. Ped. Ped. Ped.
Seg. Seg. Intersect Fac. LOS Facility
LOS # LOS # (#) LOS
1 2.46 2.88 3.02 C
2 2.47 4.23 3.32 C
3 2.90 2.24 3.02 C
4 3.20 2.24 3.12 C
5 2.79 4.29 3.44 C
Corridor 3.17 C
Ped. Ped. Ped. Ped.
Seg. Seg. Intersect Fac. LOS Facility
LOS # LOS # (#) LOS
1 3.07 2.88 3.21 C
2 3.08 4.23 3.51 D
3 3.50 2.24 3.21 C
4 3.80 2.24 3.31 C
5 3.39 4.29 3.63 D
Corridor 3.37 C
Ped Segment LOS = C
Ped Segment LOS = B
Bicycle Lanes
• Bicycle LOS is very sensitive to vehicle traffic volume and
speed
– Difficult to modify on a corridor such as 185th
• Bicycle LOS can help quantify and compare
benefits/disadvantages of
– road widening
– bicycle lane widening
– on-street parking
– traffic calming (reducing volume and speed)
– access management
• Highly suited to identifying most bicycle friendly routes
• Existing (4 routes w/ 25 – 50 minute headways, appx. 10
buses per hour)
• Provide shelters at every stop and all routes with 4 buses/hour
• Downgrade transit service to one route on 30-minute
headways
Transit Improvements
Street Score LOS
Auto 2.77 C
Transit 2.56 B
Bike 3.43 C
Ped 3.37 C
Street Score LOS
Auto 2.77 C
Transit 2.28 B
Bike 3.47 C
Ped 3.35 C
Minor increase in transit LOS
Significant decrease in transit LOS
Street Score LOS
Auto 2.77 C
Transit 4.18 D
Bike 3.47 C
Ped 3.35 C
• Existing
• Exchange one travel
lane for landscape
strip and wider bike
lanes and sidewalks
Removal Of Travel Lane
Street Score LOS
Auto F (v/c>1)
Transit 2.61 B
Bike 3.42 C
Ped 3.66 D
Street Score LOS
Auto 2.77 C
Transit 2.56 B
Bike 3.43 C
Ped 3.37 C
Decreased LOS for Peds because of
increased volume in outside lane and
intersection crossing delay. *Need to
consider adjustment of traffic
volumes and speeds if you reduce
vehicle capacity.
Reduced traffic volumes, increased
stops/mile.
Street Score LOS
Auto 3.13 C
Transit 2.56 B
Bike 3.17 C
Ped 3.32 C
Russell Street Corridor, Missoula Montana
1.5 Mile-long Study Area
1 of 5 Bridge Crossings
Parallels US 93 (major commercial corridor)
2/3 lane cross section with limited
pedestrian/bicycle facilities
ADT volumes of 25,000 (north end) to 20,000
(south end)
Important route for bicycle commuters
Primarily residential neighborhoods around
south half
Industrial and commercial uses around north
half
3rd St
14th St Mount Ave
5th St
Broadway St N
Ru
ss
ell
St
70
Alternative Analysis – Cross-section and Traffic
Control
Bicycle, Pedestrian, and Transit LOS Summary
• Overall LOS for Alternatives and Option
DEIS Alternatives
Alt 1 – No Build
Existing 3 Lane
Volumes 5 Lane
Volumes Alt 2 Alt 3 Alt 4 Alt 5-R Option 6
Bike LOS - Southbound F F F F F E E F
Bike LOS – Northbound F F F F F E E F
Ped LOS - Southbound D D E C C C C D
Ped LOS – Northbound D D D C C C C C
Transit LOS - Southbound D D D D D D D D
Transit LOS – Northbound D D D D D D D D
Legend
LOS = A, B, or C
LOS = D
LOS = E or F
Overall Analysis Summary
DEIS Alternatives
Alt 1 (No Build)
Performance Measure 3-Lanes 5-Lanes Alt 2 Alt 3 Alt 4 Alt 5-R Option 6
Intersection Operations (LOS) 6 7 3 3 1 2 5
Corridor Operations (Travel Time) 2 3 4 4 1 4 7
Safety (Predicted Average Crash Frequencies)
6 7 2* 1* 4 3 5
Pedestrian LOS 6 7 3 3 1 1 5
Bicycle LOS 5 7 3 3 1 2 6
Transit LOS 2 2 1 1 1 1 1
* Best ranking due in large part to lower traffic volume scenario (3 lane demand versus 5 lane demand).
Summary
• Alternative modes will be integrated into the 2010 HCM far
better than before
• Urban street LOS method will facilitate ”complete streets”
evaluations
– Relative service quality provided for each mode’s
travelers
– Trade-offs of different improvement alternatives or
future demand scenarios can be evaluated
• Provides agencies a way to quantify the relative benefits
and disadvantages of roadway cross-section standards
and design modifications
• Provides a methodology for multi-modal performance
standards or alternative mobility standards
MMLOS Benefits and Applications
• Allows the testing of various multi-modal goals/strategies tailored to
individual corridors.
– Different performance criteria could be applied based on the
facilities’ intended purpose and function.
• Provides a comparison between different travel modes at the same
relative scale based on user perception.
• Provides agencies a way to quantify the relative benefits and
disadvantages of roadway cross-section standards and design
modifications.
• Some important policy considerations:
– Vehicular/Pedestrian/Bicycle/Transit Hierarchy?
– Multi-modal LOS standards?
NCHRP 3-70 Resources
• http://tes.kittelson.com/ (past events)
– Presentation
– Analysis spreadsheet
• Developed by Dowling Associates
• “Research quality”: no error-checking, unsupported
– Anticipated that commercial software developers will incorporate
the method into their HCM-implementing software after the HCM is
released in late 2010
• Final Report (NCHRP Report 616):
– http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_616.pdf
• User’s Guide (NCHRP Web Document 128):
– http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_w128.pdf