Scenario Planning: U.S. Experience

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 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


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


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


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)


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


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.


Why Develop Scenarios?Why Develop Scenarios?


“ 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


http://images.google.com/imgres?imgurl=http://www.newwest.net/images/thumbnails_feature/envision_missoula_sp_thumb.gif&imgrefurl=http://discoveringurbanism.blogspot.com/2007_11_01_archive.html&usg=__y6CCGQTcR5J8gHc4LRb00xwiU0g=&h=83&w=250&sz=6&hl=en&start=2&sig2=ZSOa6Kib2ZxF8R37nDjGYw&itbs=1&tbnid=WWMDkVQYCFAHuM:&tbnh=37&tbnw=111&prev=/images?q=envision+missoula&hl=en&sa=G&gbv=2&tbs=isch:1&ei=zr6-S_6fM42AtgOftYXhAw

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)


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.”


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


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.


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


PERFORMANCE PERFORMANCE MEASURESMEASURES

GOING BEYOND CONGESTION AND TRAVEL TIME


Multi-modal Performance MeasuresMulti-modal Performance Measures

Policy Objectives1. Congestion2. Mobility3. Accessibility4. Sustainability5. Livability


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


Envision Missoula IndicatorsEnvision Missoula Indicators


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%

Thank You!Eric N. [email protected]


THE END

USING TRAVEL USING TRAVEL DEMAND MODELSDEMAND MODELS

SOME CONSIDERATIONS AND CAUTIONS


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


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


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


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


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)


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”


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


Thank You!Eric N. [email protected]


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Documents

Scenario Planning: U.S. Experience