1. The 2010 Highway Capacity Manual
Richard Dowling

2. The Highway Capacity Manual
4 Editions & 1 Update from 1950 to 2000
HCM 2000
24,500 copies distributed (14% metric)
Another 500 copies for the 2011 PE Exam
Most fervent readers:
Students and software developers
Everybody using traffic analysis software uses HCM

3. Major Changes for 2010 Guidance on Integrating Microsimulation and HCM
Multimodal (Complete Streets) LOS Analysis
Software
Active Traffic Management
Partially Electronic Format
New HCM 2010 Support Website

4. Presentation Outline Content, Format, Schedule, Software
Technical Innovations
Uninterrupted flow facilities (freeways, rural highways)
Interrupted flow facilities (urban streets, signals)
Alternative Methods (microsimulation)
Active Traffic Management

5. Format and Content - It won’t come entirely in printed form
- One part will come entirely in electronic form
- Software: source code available to all
- A website for extra materials

6. Organization of Manual
Volume 1 – Concepts
Volume 2 – Uninterrupted Flow Facilities
Freeways, rural highways, rural roads
Volume 3 – Interrupted Flow Facilities
Urban arterials, intersections, roundabouts
Signals at freeway interchanges,
Bicycle and Pedestrian paths
Volume 4 – Supplemental Materials

7. Vol.1 – Concepts of Capacity
Target Audience: Managers, Students
Nine chapters that cover…..
Concepts
Traffic flow, capacity, quality of service
Modal characteristics
Capacity Analysis Applications
How to apply the HCM
How and when to use microsimulation
Interpretation and presentation of results

8. Vol. 2 – Uninterrupted Flow Facilities
Target Audience: technical people
Six chapters on:
Freeways and their component sections
Basic sections, ramp merge/diverge, weaving
Multi-lane rural highways
Two-lane rural roads

9. Vol. 3 Interrupted Flow Facilities
Target Audience: Technical and professional people
Eight chapters on:
Urban arterials
Signalized intersections
Unsignalized intersections
Roundabouts
Signals at freeway interchanges
Bike and pedestrian paths
Multimodal Level of Service

10. Vol. 4 – Supplemental Materials
Target Audience: Engineers and programmers
12 chapters, all electronic, on the web
More detailed descriptions of methods
Worked example problems
Annotated software source code
Technical reference library
HCM Application Guide
New: Active Traffic Management

11. Software Software Will not compete with commercial software
Source code available to all
Illustrates how to program the methods
Can be used to verify commercial software
Will not compete with commercial software
Will have very limited user interface
Will work only for simple and limited example problems

12. Website

13. Publication Schedule
In TRB Production
Publication December 2010

14. Technical Innovations
Uninterrupted Flow Facilities
Interrupted Flow Facilities

15. Uninterrupted Flow Facilities
Technical Innovations
New speed-flow equations
New freeway analysis software
New weaving method
Service volume tables

16. Freeway Speed-Flow Curves
Free-Flow Speed
No longer function of number of lanes
Ramp density substituted for interchange density
New curve for 75 mph free-flow speed
Speed does not drop until 1200 vph/ln reached

17. Source: Draft HCM 2010 Materials, Kittelson & Associates

18. Weaving Sections Changes to Current Method New weaving section types
New method for estimating speed
Weaving length dependent on demands.
New method for estimating capacity

19. Freeway Facility Analysis
Modifications to reflect changes in other chapters
New software implementation (FREEVAL)
Updated capacity information for:
Work Zones
Weather (rain, snow, wind, visibility)
Incidents

20. Analysis Over Time & Space
D/C
SS 1
SS 2
SS 3
SS 4
SS 5
SS 6
16:00
0.68
0.75
0.72
0.80
0.73
16:30
0.85
0.82
0.93
17:00
0.87
0.97
0.90
1.03
17:30
0.98
18:00
0.78
0.70
18:30
0.58
0.62
0.60
MPH 63 62 61 60 58 57 59 29 41 19 15 35 27 48 64

21. FREEVAL Outputs (Speed)

22. Service Volume Tables
Rural Freeway ADT’s (1000’s)

23. Multi-lane Highways
Bicycle LOS analysis added
Service volume tables

24. Two Lane Highways Two-way analysis methodology dropped.
Some revisions to curves and tables.
New road class added for built-up areas.
LOS based on % free-flow speed (FDOT)
Bicycle LOS on two-lane highways.
Service volume tables

25. Interrupted Flow Facilities
Technical Innovations:
New multimodal level of service method
New methods for arterials and signals
New method for signals in an interchange
New method for roundabouts

26. Multimodal Level of Service
Simultaneous analysis of LOS for auto drivers, bus riders, bicyclists, pedestrians.
A method for allocating scarce street right-of-way to the various modal users of the street.

27. Sharing the Street – Complete Streets
Mode
Before
After
Auto C D
Bus B
Bicycle F
Pedestrian E
Before
After

28. Urban Street Analysis Predicts Stops (New), Speed, Queues
Models signal coordination
force offs, yields
Mixed street: signal, stops, roundabout
Sensitive to access management
driveways, median breaks
Service Volume Table

29. Urban Street Service Volumes

30. Signalized Intersection Updates
Incremental queue analysis (IQA)
Traffic actuated signals
Min. green, passage time, recall, dual entry, Dallas phasing, simultaneous gap out, detector length.
Left turn queue overflow check (New)
Volume/capacity ratio check (New)
Level of service for bicycles and pedestrians (New)

31. Incremental Queue Analysis
Delay polygon for shared left-through lane with permitted lefts
Old
New
Queued Vehicles
Time

32. Left Turn Overflow Check (New)
If left turn overflow occurs, review results

33. Volume/Capacity Ratio Check
if: v/c > 1.00
Then the signalized intersection LOS is “F”

34. Two-Way Stop Updates Extended to 6-lane arterials. U-turns
Analysis of shared lanes, short lanes
Pedestrian crossings analysis

35. All Way Stop Updates Queuing model added
Explicit guidance for 6-lane streets

36. Roundabouts Update New methodology based on US Research
NCHRP Report 572
U.S. Capacities lower than rest of world
LOS based on delay
Same thresholds as for unsignalized intersections
Roundabouts held to higher standard than signals

37. Roundabout Capacity Slide courtesy of:
Lee Rodegerdts, Kittelson & Associates

38. Capacity: 1 lane
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates

39. Capacity: 2x1 lane
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates

40. Capacity: 1x2 lane
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates

41. Capacity: 2x2 lane
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates

42. Interchange Ramp Terminals
Analysis of Diamonds, Par-clos, Roundabouts
Methodology for choosing interchange types
Lost capacity due to:
Queue spillbacks
Uneven lane utilization
Demand starvation

43. Alternative Methods When and how to apply microsimulation.
Comparing microsimulation results to HCM results

44. Chapter 6: HCM and Alternative Tools
Planning Methods Based on the HCM
Alternative Methods (Microsimulation)
Traffic modeling concepts
Application guide
Framework to apply HCM + microsimulation
Comparison of performance measures
Selection of traffic models

45. Chapter 7 Interpreting Results
Uncertainty and Variability
Concepts, Sources, Sensitivity Analysis
Uncertainty and Sensitivity of HCM results
Comparing HCM and Microsimulation Results
Framework for comparing HCM/microsim results
Specific guidance provided in facility specific chapters
Presentation of HCM/Microsimulation Results
Significant digits for reporting

46. Microsimulation vs HCM Delay
Accumulated
Vehicles
Arrivals
HCM
Delay
Departures
Modelos de micro-simulacion cuentan solo la demoras que se acumulan durante el periodo de análisis.
Los métodos del manual de capacidad incluyen la demora extra que sufren los vehículos que quedan en la cola cuando termina el periodo de análisis.
Queue
Dissipation
Time
Time
Analysis
Period

47. Active Traffic Management
New chapter on the continuous real time monitoring and management of both demand and capacity
Se trata del monitoreo continuo y el control dinámico del tránsito
Ejemplos son….

48. Active Traffic Management
ATM is a comprehensive approach to optimizing the operational performance of the roadway system through monitoring and control of systems operations and demands.
Examples
Demand Metering, Congestion Pricing, Managed Lanes, Adaptive Control, Speed Harmonization, Traveler Information Systems, Incident Management, Work Zone Management

49. Active Traffic Management
Provides basic information on active traffic management measures
Provides references from the literature
Describes applicability of HCM or microsimulation methods to evaluation
New methodology coming in one year

50. Conclusion – The New HCM
New tools for multimodal planning
Guidance on the use of microsimulation
New methods for freeways and streets
Service volume tables for planning applications
New material to aid software programmers
Information on Active Traffic Management

51. Questions/Comments Richard Dowling Dowling Associates, Oakland, CA
ext 120
Pero antes Quiero agradecer a dos personas muy importantes en el desarrollo del Manual
Mark Vandehey, el autor/editor en jefe del Manual Y
Richard Cunard, de “transportation research board” que coordina la publicación del manual para 2010.