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