GreenSTEP Statewide Transportation Greenhouse Gas Model

GreenSTEP GreenSTEP Statewide Transportation Statewide Transportation Greenhouse Gas ModelGreenhouse Gas Model

Cutting Carbs ConferenceDecember 3, 2008

Brian GregorODOT Transportation Planning Analysis

Unit

What are models?What are models?

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We Are All ModelersWe Are All Modelers

Highway Expansion

Sprawl

More Travel

Any time that logic is used to predict the consequences of decisions, a model is used to structure the reasoning process. Most often that is a mental model.

Whatever shall we do?

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Conflicts Arise from Conflicts Arise from Differences in Mental ModelsDifferences in Mental Models

Highway Expansion

Sprawl

More Travel

Highway Expansion

More Travel

Sprawl

You’re wrong!

No You Are!

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Formal Models are Needed for Formal Models are Needed for Analyzing Complex SystemsAnalyzing Complex Systems

Well structured models:

• Can account for many complex interactions

• Maintain logical consistency in addressing interactions

• Provide a more complete accounting of effects

• Allow policies to be tested in a reasonable amount of time

• Help to resolve conflicts between differing points of view

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Steps in Model Development Steps in Model Development ProcessProcess• Design

– Define model scope, structure, and components

• Estimation– Use data to develop mathematical functions and

algorithms for model components

• Calibration– Adjust function parameters and algorithms to match

observed values (e.g. % zero vehicle households)

• Validation– Check that overall model behavior is reasonable

Models are complex, and may be difficult to understand, but should not be black boxes.

What is GreenSTEPWhat is GreenSTEP

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GreenSTEP ModelGreenSTEP Model

• Greenhouse gas State Transportation Emissions Planning Model

• Why develop GreenSTEP– The OGWC needs to be able to analyze the effects

of transportation and land use strategies for reducing GHG emissions statewide.

– Existing land use and transportation models can’t be used to do the required analysis on a statewide basis in the time available.

• Statewide scope of analysis required• A wide range of factors need to be analyzed• Run-time issues

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GreenSTEP Model GreenSTEP Model RequirementsRequirements• Develop statewide forecasts of GHG emissions from

transportation sources in response to various policy approaches and other factors (e.g. fuel prices).

• Be responsive to regional differences including differences between metropolitan areas, other urban areas and rural areas.– Is not a substitute for the use of metropolitan

transportation and land use models for regional planning

• Run relatively quickly so that a number of iterations of scenario development and testing can occur.

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Factors for Model to Factors for Model to AddressAddress

• Demographic changes

• Relative amounts of development occurring in urban and rural areas

• Metropolitan and other urban area densities and urban form

• Amounts of metropolitan area public transit service

• Highway capacity

• Vehicle fuel efficiency

• Electric vehicles

• Fuel prices

• Other vehicle pricing

• Demand management

• Congestion effects

• Vehicle operation and maintenance

• Carbon content of fuels – including well to wheels impacts

• CO2 production from electrical power generation

Model StructureModel Structure

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GreenSTEP Model StructureGreenSTEP Model StructurePopulation Projection by

Age Cohort(OEA County Forecasts)

Create Synthetic Households by County to Represent Population Projection• Number of persons by age• Income

Calculate Population Densities and Urban Mixed-Use Characteristics where Households are Located

Urban Growth Boundary Expansion Rates

Average Fleet MPG by Type

Primary EV Driving Range and Proportion of VMT in Range to be EV

Calculate Vehicle Fleet Characteristics:

• Vehicle ages, types by income• Average MPG• Gas and diesel proportions• Proportion of Mileage that is EV

Rate of Transit Revenue Mile Growth

Rate of Freeway Lane-Mile Growth

Household Age Structure Model

Household Income Model

Proportions of Growth Occurring in

Metropolitan, Other Urban, and Rural Areas

Calculate Freeway and Public Transit Supply Levels

Census Tract Density Model

Models of Age and Type of Vehicle by Income

Group

Model of Daily Miles Driven by Vehicle by Population Density

Calculate Vehicle Ownership Vehicle Ownership Model

State Average Per Capita Income Growth

Calculate Annual Household VMT

Household DVMT Models

- Metropolitan Area-Other Urban and Rural

Urban Mixed-Use Model

Urban Mixed-Use Assumptions

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Demand Management Assumptions

Demand Adjustment Factors

Calculate Demand Management Adjusted VMT

Electric Power Cost Assumptions

VMT Tax Policy Assumptions

Fuel Lifecycle Carbon Content

CO2 Production per KWH

Household DVMT Models

- Metropolitan Area-Other Urban and Rural

Vehicle Ownership Model

Calculate Household Travel Cost Increase Over 2000 Levels and

Adjust Household Income

Fuel Cost Assumptions

Recalculate Vehicle Ownership Based on Adjusted Household

Income

Recalculate Annual Household VMT Based on Adjusted Household

Income

Public Transit VMT Calculated from

Revenue Miles ( above )Calculate Fuel Consumption, Electric Power Consumption, and

Greenhouse Gas Emissions Average Fleet MPG and MPKwh

( calculated above )

Vehicle Fleet MPG & MPKwh

Statewide Population Projection

Truck VMT ModelCalculate Truck VMTState Average Per

Capita income Growth

Vehicle Maintenance & Operations Assumptions

Model Sensitivity TestingModel Sensitivity Testing

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Scenario

Urbanized AreaPopulationDensity

Freeway Lane-Miles Per Capita

Transit Revenue Miles Per Capita

Percent Urban Mixed-Use

Average Vehicle Ratio

Average Household DVMT

1 7000 0.4 40 100 0.8 38.42 7000 0.4 40 50 0.85 42.83 7000 0.4 20 50 0.94 474 7000 0.65 20 50 0.94 51.25 2500 0.65 20 11 1.07 656 2500 0.9 20 11 1.08 69.67 2500 0.9 10 11 1.09 71.58 2500 0.9 10 0 1.1 73.2

Test of Model Sensitivity to Land Test of Model Sensitivity to Land Use and Transportation InputsUse and Transportation Inputs

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Scenario







1 7000 0.4 40 100 0.8 38.42 7000 0.4 40 50 0.85 42.83 7000 0.4 20 50 0.94 474 7000 0.65 20 50 0.94 51.25 2500 0.65 20 11 1.07 656 2500 0.9 20 11 1.08 69.67 2500 0.9 10 11 1.09 71.58 2500 0.9 10 0 1.1 73.2


Approximate density of Los Angeles

Approximate density of Atlanta

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Scenario







1 7000 0.4 40 100 0.8 38.42 7000 0.4 40 50 0.85 42.83 7000 0.4 20 50 0.94 474 7000 0.65 20 50 0.94 51.25 2500 0.65 20 11 1.07 656 2500 0.9 20 11 1.08 69.67 2500 0.9 10 11 1.09 71.58 2500 0.9 10 0 1.1 73.2


Approximate freeway supply of New York

Approximate freeway supply of Houston

Approximate freeway supply of Minneapolis

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Scenario







1 7000 0.4 40 100 0.8 38.42 7000 0.4 40 50 0.85 42.83 7000 0.4 20 50 0.94 474 7000 0.65 20 50 0.94 51.25 2500 0.65 20 11 1.07 656 2500 0.9 20 11 1.08 69.67 2500 0.9 10 11 1.09 71.58 2500 0.9 10 0 1.1 73.2


Approximate transit supply of Miami

Approximate transit supply of Detroit

Approximate transit supply of Seattle

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Scenario







1 7000 0.4 40 100 0.8 38.42 7000 0.4 40 50 0.85 42.83 7000 0.4 20 50 0.94 474 7000 0.65 20 50 0.94 51.25 2500 0.65 20 11 1.07 656 2500 0.9 20 11 1.08 69.67 2500 0.9 10 11 1.09 71.58 2500 0.9 10 0 1.1 73.2


No places are urban mixed-use

All places are urban mixed-use

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Scenario







1 7000 0.4 40 100 0.8 38.42 7000 0.4 40 50 0.85 42.83 7000 0.4 20 50 0.94 474 7000 0.65 20 50 0.94 51.25 2500 0.65 20 11 1.07 656 2500 0.9 20 11 1.08 69.67 2500 0.9 10 11 1.09 71.58 2500 0.9 10 0 1.1 73.2


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ConclusionsConclusions

• GreenSTEP can be used to evaluate a large number of different policies and other factors on GHG emissions: land use, transportation, prices, vehicle characteristics, fuels, etc.

• GreenSTEP evaluates interactions between factors: e.g. density -> vehicle ownership -> vehicle travel

• GreenSTEP includes new modeling components that we will be able to combine with other models, statewide and urban for modeling GHG emissions.

Documents

GreenSTEP Statewide Transportation Greenhouse Gas Model