Incorporating a land consumption model with a statewide travel model

1. Incorporating a land consumption model with a statewide travel model Laurence Brown Indiana DOT John Ottensmann Indiana University-Purdue University Indianapolis Jon Fricker Purdue University Li Jin Kittelson & Associates, Orlando, FL

2. Introduction • Indiana State Travel Demand Model (ISTDM) • Developed by Indiana Department of Transportation • LUCI and luci2 Urban Simulation Models for central Indiana • Developed by Center for Urban Policy and the Environment • INTRLUDE (Integrated Transportation Land-Use Demand Estimation) Model • luci2 INDOT Statewide Model • Integrated with ISTDM

3. TAZs in ISTDM • 4579 internal TAZs • 141 external TAZs • Same geographical units used in luci2 INDOT Statewide Model • TAZs around urban areas split to reflect sewer service availability and implement urban growth boundary option

4. luci2 INDOT Statewide Model • Simulates new urban development for TAZs • Allocates population growth and residential development • Allocates employment growth and related employment-related development • Optionally forecasts growth in local-service employment • Integrated with travel demand model • Uses travel times generated by travel demand model • Outputs population and employment for travel demand model

5. Major model data sources • LandSat imagery for 1985, 1993, 2000 • Land cover classification • Reclassification to estimate residential and employment-related land use • Population and employment data from travel demand model

6. Prediction models estimated • Models estimated using data by TAZ for 2000, change from 1995-2000 • Probability of residential development • Density of residential development • Probability of employment-related development • Density of employment-related development • Change in local-service sector industry employment

7. How model simulates urban development • Works in 5-year simulation periods • Simulation driven by exogenous forecast of population growth for entire state

9. Prediction of employment change • Uses employment forecast by TAZ from travel demand model forecast for 2030 • Option to predict local-service employment change • Predictors of local-service employment change • Accessibility to population change • Change in urban land in TAZ in previous period

10. Prediction of employment-related development Predict employment density by TAZ Allocate new employment-related development to accommodated predicted employment growth For split TAZs, new development allocated to portion with highest predicted probability of employment-related development

11. Prediction of residential development Predict probability of conversion of nonurban land to residential use by TAZ Aggregate logit model Accessibility to employment change Availability of sewer utility service Predict population density by TAZ Accessibility to employment Availability of sewer utility service Probabilities adjusted uniformly to accommodated specified population growth

12. Scenario options in model Population growth Density of residential development Sewer expansion Agriculture land preservation Urban growth boundaries Increased dispersal of development Importance of accessibility to employment Employment changes in specific TAZs

13. Model implementation Input: travel times from ISTDM Outputs: population and employment by industry for ISTDM Interface Original model interactive, with options specified by user Final version run from command line Options specified in a scenario definition file Population and employment output to files for use by travel demand model

14. INtegrated TRansportation Land-Use Demand Estimation (INTRLUDE) Model • ISTDM is implemented in TransCAD • Integration of luci2 Model and travel demand model accomplished using the TransCAD GIS Developer’s Kit (GISDK) • Provides user interface to specify options for simulation, including options for the luci2 Model • Manages exchange of data between the ISTDM and the luci2 Model • Runs the simulations in the ISTDM and the luci2 Model

15. INTRLUDE simulation specifications • Overall simulation • Target year • luci2 Model • Whether to predict local-service employment • Population growth rate • Other scenario options • ISTDM • Network for each simulation year

16. INTRLUDE Model interface

17. INTRLUDE simulation process • Begins with luci2 simulation of change from 2000 to 2005 • Model uses 2000 travel times from ISTDM • Model outputs population and employment for 2005 • ISTDM simulates travel in 2005 • Model uses output from luci2 and network specified for 2005 • Model outputs travel times (congested skim tree) for 2005 • luci2 simulates change from 2005 to 2010 • Process continues to target year

18. INTRLUDE Model interaction

19. ISTDM and INTRLUDE population density forecasts ISTDM INTRLUDE

20. Comparison of ISTDM and INTRLUDE population density forecasts • Generally high correlation between INTRLUDE and ISTDM forecasts • INTRLUDE forecasts show more variation spatially than ISTDM forecasts • More areas of higher density around urban areas • Overall greater spread of population growth over broader areas

21. ISTDM versus INTRLUDE population density by TAZ Correlation r = 0.97

22. VMT forecasts for 2030

23. VHT forecasts for 2030

24. General INTRLUDE applications • Comparison of ISTDM and INTRLUDE simulation results for planned improvements • Sensitivity of model forecasts to luci2 Model scenario options • Simulations with planned intermediate-year network improvements included in model

25. Specific INTRLUDE applications • Use in early stages of project scoping to - • Compare multiple project scenarios • Consider land use consumption of projects • Large upgrades and new projects of specific interest – • Indianapolis outer loop expressway (CISTMS) • U.S. 31 upgrade to limited access • I-69 new terrain/upgrade • Illiana expressway

26. INTRLUDE assessment of effects of changed conditions and forecasts • Effects of major employment changes not included in INDOT 2030 forecast • Effects of recent downward adjustment in population and employment forecasts