Highlights of Freeway Analysis Changes for 2010 HCM

Report
1
The
2010 Highway
Capacity Manual
Richard Dowling
The Highway Capacity Manual
2

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
Major Changes for 2010
3

Guidance on Integrating Microsimulation and HCM

Multimodal (Complete Streets) LOS Analysis

Software

Active Traffic Management

Partially Electronic Format

New HCM 2010 Support Website
Presentation Outline
4

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
Organization of Manual
6

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
Vol.1 – Concepts of Capacity
7

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
Vol. 2 – Uninterrupted Flow Facilities
8

Target Audience: technical people

Six chapters on:
 Freeways
 Basic
and their component sections
sections, ramp merge/diverge, weaving
 Multi-lane
rural highways
 Two-lane rural roads
Vol. 3 Interrupted Flow Facilities
9

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
Vol. 4 – Supplemental Materials
10

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
Software
11

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
Website
12
Publication Schedule
13

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
Freeway Speed-Flow Curves
16

Free-Flow Speed
 No
longer function of number of lanes
 Ramp density substituted for interchange density

New curve for 75 mph free-flow speed

Speed does not drop until 1200 vph/ln reached
17
Source: Draft HCM 2010 Materials, Kittelson & Associates
Weaving Sections
18

Changes to Current Method
 New
weaving section types
 New method for estimating speed
 Weaving length dependent on demands.
 New method for estimating capacity
LS
LB
Freeway Facility Analysis
19

Modifications to reflect changes in other chapters

New software implementation (FREEVAL)

Updated capacity information for:
 Work
Zones
 Weather (rain, snow, wind, visibility)
 Incidents
Analysis Over Time & Space
20
D/C
16:00
16:30
17:00
17:30
18:00
18:30
MPH
16:00
16:30
17:00
17:30
18:00
18:30
SS 1
0.68
0.75
0.87
0.82
0.73
0.58
SS 2
0.75
0.85
0.97
0.90
0.78
0.62
SS 3
0.72
0.82
0.90
0.85
0.73
0.58
SS 4
0.72
0.82
0.90
0.85
0.73
0.58
SS 5
0.80
0.93
1.03
0.98
0.80
0.62
SS 6
0.73
0.82
0.93
0.85
0.70
0.60
63
62
60
61
62
64
62
60
57
59
62
64
63
61
59
19
62
64
63
61
29
15
27
64
61
58
41
35
48
64
62
61
58
60
63
64
FREEVAL Outputs
Space Mean(Speed)
Speed Contours (mi/hr)
21
60.00
Speed (mi/hr)
50.00
40.00
30.00
20.00
10.00
5
0.00
1
2
3
3
4
5
6
7
Segment Number
8
9
1
10
11
Time Interval
Service Volume Tables
22

Rural Freeway ADT’s (1000’s)
Multi-lane Highways
23

Bicycle LOS analysis added

Service volume tables
Two Lane Highways
24

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
Multimodal Level of Service
26


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.
Sharing the Street – Complete Streets
27
Mode
Before
After
Auto
C
D
Bus
B
C
Bicycle
F
D
Pedestrian
E
E
Before
After
5’
8’
5’
12’
10’
70 ft ROW
12’
5’
8’
5’
Urban Street Analysis
28

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
Urban Street Service Volumes
29
Signalized Intersection Updates
30

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)
Incremental Queue Analysis
31
Queued Vehicles
Delay polygon for shared left-through lane with permitted lefts
Old
New
Time
Left Turn Overflow Check (New)
32
If left turn overflow
occurs, review results
Volume/Capacity Ratio Check
33

if: v/c > 1.00

Then the signalized intersection LOS is “F”
Two-Way Stop Updates
34

Extended to 6-lane arterials.

U-turns

Analysis of shared lanes, short lanes

Pedestrian crossings analysis
All Way Stop Updates
35

Queuing model added

Explicit guidance for 6-lane streets
Roundabouts Update
36

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
Roundabout Capacity
37
1,400
1,200
Capacity (pc/h)
1,000
Capacity of one-lane entry or right lane of
two-lane entry against two conflicting lanes
800
Capacity of left lane of two-lane entry
against two conflicting lanes
600
400
Capacity of one-lane or either lane of twolane entry against one conflicting lane
200
Dashed regression extrapolated beyond the data
0
0
200
Slide courtesy of:
Lee Rodegerdts, Kittelson & Associates
400
600
800
1,000
1,200
1,400
Conflicting Flow Rate (pc/h)
1,600
1,800
2,000
Capacity: 1 lane
1,400
1,200
Capacity (pc/h)
1,000
Capacity of one-lane entry or right lane of
two-lane entry against two conflicting lanes
800
Capacity of left lane of two-lane entry
against two conflicting lanes
600
400
Capacity of one-lane or either lane of twolane entry against one conflicting lane
200
Dashed regression extrapolated beyond the data
0
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
Conflicting Flow Rate (pc/h)
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates
Capacity: 2x1 lane
1,400
1,200
Capacity (pc/h)
1,000
Capacity of one-lane entry or right lane of
two-lane entry against two conflicting lanes
800
Capacity of left lane of two-lane entry
against two conflicting lanes
600
400
Capacity of one-lane or either lane of twolane entry against one conflicting lane
200
Dashed regression extrapolated beyond the data
0
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
Conflicting Flow Rate (pc/h)
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates
Capacity: 1x2 lane
1,400
1,200
Capacity (pc/h)
1,000
Capacity of one-lane entry or right lane of
two-lane entry against two conflicting lanes
800
Capacity of left lane of two-lane entry
against two conflicting lanes
600
400
Capacity of one-lane or either lane of twolane entry against one conflicting lane
200
Dashed regression extrapolated beyond the data
0
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
Conflicting Flow Rate (pc/h)
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates
Capacity: 2x2 lane
1,400
1,200
Capacity (pc/h)
1,000
Capacity of one-lane entry or right lane of
two-lane entry against two conflicting lanes
800
Capacity of left lane of two-lane entry
against two conflicting lanes
600
400
Capacity of one-lane or either lane of twolane entry against one conflicting lane
200
Dashed regression extrapolated beyond the data
0
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
Conflicting Flow Rate (pc/h)
Slide courtesy of: Lee Rodegerdts, Kittelson & Associates
Interchange Ramp Terminals
42

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
Chapter 6: HCM and Alternative Tools
44

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
Chapter 7 Interpreting Results
45

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
Microsimulation vs HCM Delay
46
Accumulated
Vehicles
Microsimulation
Delay
HCM
Delay
Analysis
Period
Queue
Dissipation
Time
Time
47
Active Traffic Management
New chapter on the continuous real time
monitoring and management of both demand
and capacity
Active Traffic Management
48


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
Active Traffic Management
49




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
Conclusion – The New HCM
50

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
Questions/Comments
51

Richard Dowling
Dowling Associates, Oakland, CA
 510-839-1742 ext 120
 [email protected]

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