scenario planning: u.s. experience
DESCRIPTION
CIVITAS Open Academy Ljubljana 15 April 2010 Eric N. Schreffler, Transport Consultant San Diego, California USA. Scenario Planning: U.S. Experience. Overview. What is Scenario Planning (U.S. context) Example: Envision Missoula Performance Measures Travel Demand Modeling. - PowerPoint PPT PresentationTRANSCRIPT
CIVITAS Open AcademyCIVITAS Open AcademyLjubljanaLjubljana15 April 201015 April 2010Eric N. Schreffler, Transport ConsultantEric N. Schreffler, Transport ConsultantSan Diego, California USASan Diego, California USA
Scenario Planning: U.S. Experience
OverviewOverview
What is Scenario Planning (U.S. context)
Example: Envision Missoula
Performance Measures
Travel Demand Modeling
Scenario Planning – Ljubljana Workshop
THE BASICSTHE BASICSWHAT ARE SCENARIO PLANNING AND VISIONING?
Scenario Planning – Ljubljana Workshop
Scenario Planning – Ljubljana Workshop
“Scenario planning is a process in which transportation professionals and citizens work together to analyze and shape the long-term future of their communities. Using a variety of tools and techniques, participants assess trends in key factors such as transportation, land use, demographics, health, etc. Participants bring the factors together in alternative future scenarios, each of these reflecting different trend assumptions and tradeoff preferences.”
Federal Highway Administration definition
U.S. DEFINITION: Scenario PlanningU.S. DEFINITION: Scenario Planning
VISIONINGVISIONING
Scenario planning complements and follows community visioning
Community visioning helps experts project future growth, economy, funding
More importantly, it establishes important community values that define livability
Scenario Planning – Ljubljana Workshop
ScenariosScenarios
Typically, scenarios include alternative growth futures and alternative investment or funding strategies
Differs from alternatives analysis, which assumes one static future
Scenario planning provides a framework for developing a shared vision for the future
It does this by analyzing various forces that affect growth and testing various future alternatives that meet area needs
Scenario Planning – Ljubljana Workshop
ScenariosScenarios Common assessment of forces that
influence growth, including: • Mobility• Economy• Health• Land use• Environment
Common assessment of factors that influence available funding
Development of transportation strategies to meet future scenarios, including consideration of trade-offs
Scenario Planning – Ljubljana Workshop
Inclusive PlanningInclusive Planning Successful plans come from early
involvement of a variety of stakeholders: • The public (as residents, voters and
travelers)• Politicians (local elected officials)• Government administrators• Special interest groups (e.g. bicycle
advocates)• Private business, including land developers• Transportation providers (e.g., public
transport)
Scenario Planning – Ljubljana Workshop
Six Steps of Scenario PlanningSix Steps of Scenario Planning
1. Define driving forces of change2. Determine patterns of interaction3. Create scenarios4. Analyze implications5. Evaluate scenarios6. Monitor indicators
Scenario Planning – Ljubljana Workshop
Benefits of Scenario PlanningBenefits of Scenario Planning Provides an analytical framework and
process for understanding complex issues. Facilitates consensus building by giving
communities the capacity to participate actively in the planning process.
Includes tools and techniques to assess the impact of transportation and other public policy choices on a community.
Allows an opportunity to recognize the impact of trade-offs among competing goals.
Yields an enhanced decision-making framework by bringing together many viewpoints.
Helps to improve management of increasingly limited resources.
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Why Develop Scenarios?Why Develop Scenarios?
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“ If you don t know where you re going, you’ll probably end up somewhere else. “
Yogi Berra New York Yankees
U.S. EXAMPLEU.S. EXAMPLEENVISION MISSOULA
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Envision Missoula ScenariosEnvision Missoula Scenarios
Missoula, Montana (population 100,000)
Scenario Planning Used to Update Long-range Transportation Plan
Three Scenarios Developed:1. Business as Usual (no vision)2. Suburban Satellites (multi-centers)3. Focus Inward (city center)
Scenario Planning – Ljubljana Workshop
Role of ScenariosRole of Scenarios
According to plan, scenarios were:“not intended to represent project lists for the plan, but rather to suggest problem-solving approaches for how Missoula can address its transportation challenges in the long term.”
Scenario Planning – Ljubljana Workshop
Visioning ExerciseVisioning Exercise Used “chips”
and “tapes”
Chips represented desired land uses
Tapes represented transport modes• Different classes of roads• Public transport services• Bicycle and pedestrian paths
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Envision Missoula AnalysisEnvision Missoula Analysis
Modeling and analysis used to show how different strategies for managing travel demand while investing in targeted infrastructure can support future system performance.
Scenario Planning – Ljubljana Workshop
Outcome of Outcome of Focus Inward Focus Inward ScenarioScenario Single In-Town Mobility District with one priority
corridor (rather than many multimodal corridors)
Increase density in city core Priority to bicycles and bike access to public
transport Multimodal center in city center ITS improvements giving priority to pedestrians Electric circulator buses Commuter rail focused on city center
destination One-way street couplets Preferential parking and commuter shuttles
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PERFORMANCE PERFORMANCE MEASURESMEASURES
GOING BEYOND CONGESTION AND TRAVEL TIME
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Multi-modal Performance MeasuresMulti-modal Performance Measures
Policy Objectives1. Congestion2. Mobility3. Accessibility4. Sustainability5. Livability
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Multi-modal Performance MeasuresMulti-modal Performance Measures
Examples• Travel time reliability (managing
congestion)• VHT – Vehicle Hours of Travel (congested
conditions)• VKT reduction (effectiveness of non-auto
modes)• Person Throughput – travelers per mile, all
modes• Average speed across corridor by all modes
(mobility)• Multi-modal Level of Service (bus and bike)• User satisfaction with travel modes
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Envision Missoula IndicatorsEnvision Missoula Indicators
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Scenario Key Strategic Elements forManaging Congestion and TravelDemand
Mobility Performance VMT
(millions)% VMT
CongestedVHT % VHT
Congested
2005 Conditions
3.09 0.5% 72,992 3%
Business as Usual
•Increase Infrastructure Supply Only• Limit transit expansion to currentplans• Low Density Development• Build and Expand Roads to Meet Demand
10.00 33.0% 712,523 78.8%
Suburban Satellites
• Invest in Multi-Modal Corridors• Manage Travel Demand in TownCenters Along Key Multi-ModalCorridors• Invest primarily in CurrentlyCommitted Roadway Projects
10.13 40.4% 965,596 85.6%
Focus Inward
• Invest in Amenities Downtown• Support One Multi-Modal Corridor• Invest primarily in CurrentlyCommitted Roadway Projects
8.50 24.5% 364,444 60.5%
USING TRAVEL USING TRAVEL DEMAND MODELSDEMAND MODELS
SOME CONSIDERATIONS AND CAUTIONS
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Why Do We Use Travel Models?Why Do We Use Travel Models?
To project travel demand into the future in order to plan for future
To assess where that travel might occur
To project car and public transport use To assess unmet needs To justify large infrastructure
investments
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Four Step Travel Demand ModelFour Step Travel Demand Model
Starts with land use analysis to project population and employment
Step 1 – Trip Generation – frequency of O & D by trip purpose
Step 2 – Trip Distribution – spatial distribution of travel by zone
Step 3 – Mode Choice – matches modes to personal attributes
Step 4 – Route Assignment – distributes travel to roads
Often used in Benefit/Cost Analysis and Environmental Impact Studies to evaluate projects
Scenario Planning – Ljubljana Workshop
Activity-based ModelsActivity-based Models Unit of travel is journey rather than trip Microsimulation framework is used to
track journeys of each individual in the study area
Stop frequency and locations are modeled
Non-motorized analyzed as a separate mode
Multimodal assignment is conducted Very data intensive
Scenario Planning – Ljubljana Workshop
Criticism of Traditional ModelingCriticism of Traditional Modeling Focus on car and public transport, not
bike/walk Reduces evaluation to time and cost factors Cannot handle mobility management
strategies Presumes we can project 20 years out (or
more) Based on population forecasts, which are
inaccurate Revealed preference presumes past behavior
continues Used as “black box” with aura of wizardry Can be misused to justify desired projects
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Issue: Lack of ValidationIssue: Lack of Validation Validation is comparing forecasted (a
priori) impacts to actual results (ex post) For nine out of ten railway projects the
study found that passenger forecasts were overestimated, with an average overestimate of 106%,
For half of all road projects, including bridges and tunnels, the study found that the difference between actual and forecast traffic was more than 20%, while for 25% of road projects the difference was more than 40%.Flyvbjerg, Holm, and Buhl (January 2006)
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Forecasting vs. ResultsForecasting vs. Results
“Evaluation” can imply both prediction of outcomes based on modeling AND measurement of actual results based on monitoring
Very important to set objectives and then evaluate programs, projects and policies to gauge fulfillment of or progress toward objectives
This is at the heart of “objective-driven, performance-based planning”
Scenario Planning – Ljubljana Workshop
Appropriate Use of ModelsAppropriate Use of Models
Modeling is only one tool in planning process
Modeled forecasts should be used to compare scenarios on a relative, not absolute basis
Off-model tools, such as TDM models and meta-simulation tools can improve projections
Limitations and uncertainty inherent in modeling should be acknowledged
Scenario Planning – Ljubljana Workshop