Incorporating a land consumption model with a statewide travel model

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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

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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

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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

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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

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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

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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

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How model simulates urban development

• Works in 5-year simulation periods
• Simulation driven by exogenous forecast of
  population growth for entire state

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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

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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

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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

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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

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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

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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
  Developers 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

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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

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INTRLUDE Model interface
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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

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INTRLUDE Model interaction
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ISTDM and INTRLUDE population density forecasts
ISTDM
INTRLUDE
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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

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ISTDM versus INTRLUDE population density by TAZ
Correlation r 0.97
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VMT forecasts for 2030
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VHT forecasts for 2030
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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

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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

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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