GreenSTEP Statewide Transportation Greenhouse Gas Model

1. GreenSTEP Statewide Transportation Greenhouse Gas Model Cutting Carbs Conference December 3, 2008 Brian Gregor ODOT Transportation Planning Analysis Unit

2. What are models?

3. Highway Expansion More Travel Sprawl We Are All Modelers 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?

4. Conflicts Arise from Differences in Mental Models Sprawl Highway Expansion Highway Expansion More Travel More Travel Sprawl You’re wrong! No You Are!

5. Formal Models are Needed for Analyzing 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

6. Steps in Model Development Process • 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.

7. What is GreenSTEP

8. GreenSTEP 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

9. GreenSTEP Model Requirements • 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.

10. Factors for Model to Address • 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

11. Model Structure

12. GreenSTEP Model Structure Population Projection by Age Cohort (OEA County Forecasts) • Create Synthetic Households by County to Represent Population Projection • Number of persons by age • Income Household Age Structure Model Household Income Model State Average Per Capita Income Growth Census Tract Density Model Urban Growth Boundary Expansion Rates Calculate Population Densities and Urban Mixed-Use Characteristics where Households are Located Urban Mixed-Use Model Proportions of Growth Occurring in Metropolitan, Other Urban, and Rural Areas Calculate Vehicle Ownership Vehicle Ownership Model Urban Mixed-Use Assumptions • Calculate Vehicle Fleet Characteristics: • Vehicle ages, types by income • Average MPG • Gas and diesel proportions • Proportion of Mileage that is EV Models of Age and Type of Vehicle by Income Group Average Fleet MPG by Type Primary EV Driving Range and Proportion of VMT in Range to be EV Model of Daily Miles Driven by Vehicle by Population Density Rate of Transit Revenue Mile Growth Calculate Freeway and Public Transit Supply Levels Rate of Freeway Lane-Mile Growth • Household DVMT Models • Metropolitan Area • Other Urban and Rural Calculate Annual Household VMT

13. Fuel Cost Assumptions Calculate Household Travel Cost Increase Over 2000 Levels and Adjust Household Income Electric Power Cost Assumptions VMT Tax Policy Assumptions Recalculate Vehicle Ownership Based on Adjusted Household Income Vehicle Ownership Model • Household DVMT Models • Metropolitan Area • Other Urban and Rural Recalculate Annual Household VMT Based on Adjusted Household Income Demand Management Assumptions Calculate Demand Management Adjusted VMT Demand Adjustment Factors Statewide Population Projection Calculate Truck VMT Truck VMT Model State Average Per Capita income Growth Vehicle Fleet MPG & MPKwh Public Transit VMT Calculated from Revenue Miles ( above ) Vehicle Maintenance & Operations Assumptions Calculate Fuel Consumption, Electric Power Consumption, and Greenhouse Gas Emissions Average Fleet MPG and MPKwh ( calculated above ) Fuel Lifecycle Carbon Content CO2 Production per KWH

14. Model Sensitivity Testing

15. Test of Model Sensitivity to Land Use and Transportation Inputs

16. Test of Model Sensitivity to Land Use and Transportation Inputs Approximate density of Los Angeles Approximate density of Atlanta

17. Test of Model Sensitivity to Land Use and Transportation Inputs Approximate freeway supply of New York Approximate freeway supply of Minneapolis Approximate freeway supply of Houston

18. Test of Model Sensitivity to Land Use and Transportation Inputs Approximate transit supply of Seattle Approximate transit supply of Miami Approximate transit supply of Detroit

19. Test of Model Sensitivity to Land Use and Transportation Inputs All places are urban mixed-use No places are urban mixed-use

20. Test of Model Sensitivity to Land Use and Transportation Inputs

22. Conclusions • 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.