Transcript Metropolitan Travel Forecasting: Current Practice and

Metropolitan Travel Forecasting:
Current Practice and Future
Direction
AMPO Travel Modeling Work
Group
December 10, 2007
Washington, DC
1863
Founding of the National Academy of
Sciences
About the National Academies
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Historic mission: form committees of experts to
address critical national issues and give advice
to the federal government and the public.
Provide independent, objective, and nonpartisan advice with high standards of scientific
and technical quality. Checks and balances are
applied at every step in the study process to
protect the integrity of the reports and to
maintain public confidence in them.
Transportation Research Board
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One of five major divisions within the
National Academies
Much of what TRB does is different from
the core mission of the National
Academies
“Metropolitan Travel Forecasting” is a
traditional National Academies policy
study
Sponsors of the Study
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Office of the Secretary, USDOT
Federal Highway Administration
Federal Transit Administration
Scope of the Study
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Determine state of practice in
metropolitan travel forecasting
Identify technical shortcomings of the
models for their intended uses
Recommend actions needed to ensure
appropriate technical processes are
being used
Committee
Martin Wachs, chairman, RAND Corporation,
MPOs
Michael R. Morris, North Central Texas COG
Charles L. Purvis, Oakland MTC
Guy Rousseau, Atlanta Regional Commission
Richard E. Walker, Metro Portland, OR
Academia
George B. Dresser, TTI, TX
Ronald W. Eash, Northwestern University, IL
Robert A. Johnston, University of California, Davis
Eric J. Miller, University of Toronto, Canada
State DOTs
Laura L. Cove, North Carolina DOT
Mary Lynn Tischer, Virginia DOT
Consultants
Thomas B. Deen
Richard H. Pratt
Technical Advisory Group
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Williams Davidson, PB Consult
Thomas Rossi, Cambridge Systematics
Williams Woodford, AECOM
Sources of Information
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Web-based survey of MPOs
In-depth interviews of MPOs
Literature review
Briefings from stakeholders
The expertise of the committee
Review of the Committee’s
Report
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Elizabeth Deakin, U of California
Mark Hallenbeck, U of Washington
Lester Hoel, U of Virginia
Charles Howard, Seattle MPO
Keith Killough, SCAG
Ron Kirby, Washington DC MPO
Frank Koppelman, Northwestern U
Keith Lawton, Consultant
Oversight of the Review Process
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Adib Kanafani, U California
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Mike Walton, U Texas
The Result
Findings
4-step model is basic approach (estimate
trips, distribute among origins and destinations,
determine mode, assign to network)
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Basic framework unchanged for over 50 years
Many variations in complexity of approach
Complex issues lead to complex models (e.g. travel
models linked with land use models)
San Francisco City, Columbus Ohio MPO, and New
York MTC have adopted more advanced
approaches
Findings (con’t)
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There is no single approach to travel
forecasting that is “correct” for all MPOs
The planning context and the nature of
questions being asked should determine
the type and complexity of model tools
employed
Findings- Current Models
Inadequate for demand analysis of many
applications
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Induced travel
Land use policies
HOT and time variable road pricing
Environmental justice
Telecommuting
Mode of access to transit
Traveler response to congested networks
Findings- Current Models (con’t)
Certain modes are poorly characterized,
e.g.
 Non-motorized travel
 Freight and commercial vehicle travel
Findings- Current Models (con’t)
Inadequate for supply-side analysisNo disaggregate estimates of volumes and
speeds on specific routes by time of day.
This affects-
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Evaluation of traffic ops improvements
Time shifting in congested networks
Evaluation of freight movement policies
Emissions estimates
Evacuation planning
Findings- Current Models (con’t)
Advanced travel models are being
developed
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Detailed representation of person and
household activities and travel
Continuous representation of time and
network performance
Implemented in a few places – appear
to work well
Findings- Current Practice
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Inadequate data
Optimism bias
Quality control
Validation errors
(FTA commended for efforts to ensure
QC)
Findings- Obstacles to Model Improvement
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Preoccupation with meeting immediate
demands of production
Fear of legal challenges
Significant budget and staff limitations
Insufficient evidence that advanced models can
be implemented for a reasonable cost and
provide significant improvements
Poor/inadequate data
Findings- Federal Government
Federal support for models
development not commensurate with
federal demands on modeling
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Reduction in federal support: in 60’s and
70’s federal investment = $15 million
annually in current dollars compared with
about $2.5 million today
Growth in federal planning and
environmental requirements for states and
MPOs has increased significantly
Overarching Recommendations
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Develop and implement new modeling
approaches better suited to providing reliable
forecasts for such applications as operational
analyses, environmental assessments,
evaluation of policy alternatives, freight
forecasts
Take steps to ensure better practice
Federal, state, regional collaboration needed
to deliver better models and practice
Recommendations for MPOs
MPOs would benefit from establishing
a national cooperative R&D program
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$4-5 million annually, governed by MPOs
themselves, for models selection,
deployment, evaluation
NYSMPO “shared cost initiative”
Recommendations for MPOs
(con’t)
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Continue peer reviews
University partnerships
Reasonableness checks of project
forecasts
Document experience with advanced
practice
Recommendations for States
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Support development of MPO
cooperative research program
Evaluate, in cooperation with MPOs,
socio-economic forecasts used for
modeling
Continue MUGs
Recommendations for Federal Gov’t
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Support and provide funding for incremental
improvements to 4-step models that are appropriate for
use.
Support and provide funding for development,
implementation, evaluation of advanced models.
Continue TMIP
Increase funding – 0.005% of federal aid is about $20
million, which is roughly comparable to the $15 million
of support in the ‘60s and ‘70s.
MPO Certification- models check-list; incorporate MPO
peer reviews
Provide flexibility for MPOs to apply models appropriate
to their needs.
Federal, State, Local
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Establish goals, responsibilities, improved training
elements, means of improving travel models—perhaps
through a steering committee of principle stakeholders.
Develop and keep current a national handbook of
practice (not a standards manual)—perhaps through
national organization that could bring partners together
& perhaps funded by MPO CRP, NCHRP, federal
government.
Document data requirements for updating travel
models, validating models, freight modeling, meeting
air quality conformity requirements, etc.
A strategy for change
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Practice resistant to change.
For the past 40 years, advances in R&D &
innovation in modeling has led to only
incremental change.
Need to break out of this cycle.
Harness the coordinated resources of each
level of government.
Return to creativity and innovation of the early
days of travel forecasting.
TRB Annual Meeting Session
Metropolitan Travel Forecasting: Current Practice and Future DirectionWednesday, January 16, 2008, 7:30 PM - 9:30 PM, Hilton Georgetown W.
Charles L. Purvis, Metropolitan Transportation Commission, presiding
Findings and Recommendations of the Report
Martin Wachs, RAND Corporation
Perspectives of Stakeholders
Gloria Shepherd, Federal Highway Administration
Ronald T. Fisher, Federal Transit Administration
Charles E. Howard, Puget Sound Regional Council
Deb Miller, Kansas Department of Transportation
Proposal for a Metropolitan Planning Cooperative Research Program
Michael R. Morris, North Central Texas Council of Governments
Summary of Discussion and Next Steps
Martin Wachs, RAND Corporation