California Statewide Integrated Model (CalSIM)


Behavioral changes in how land is used in California and the individual travel choices people make hinges on the combined actions of local government, California-based businesses, and individual households. Efforts to create more sustainable communities require cooperation and coordination at many levels, and ULTRANS researchers have played a valuable role in helping state and regional agencies work together toward this goal. CalSIM is a comprehensive integrated modeling tool designed to advance our ability to make wiser land use and transportation decisions that include consideration of environmental, economic and equity impacts both regionally and at the state level. We currently offer modeling advice and support to Caltrans, as well as four major Metropolitan Planning Organizations (MPOs) and fourteen smaller Councils of Government (COGs) in California. CalSIM is an ambitious attempt to combine a host of relevant components of the land use system, including those related to transportation, throughout the state of California.

CalSIM assesses and depicts the interregional effects of major changes (economic, land use, environmental, and other co-benefits) resulting from various transportation investments. It uses the PECAS system as its modeling platform. PECAS (Production, Exchange, Consumption, Allocation System) is designed for simulating spatial economic systems. It operates by examining submarkets for various goods, services and factors with space (land and floorspace) based on development event probabilities. The PECAS modeling system is currently being used in several contexts throughout North America including Atlanta, Baltimore, Oregon, and Miami. PECAS is a recently-designed generalized approach for simulating spatial economic systems. It operates by clearing spatial submarkets for various goods, services and factors in a short run equilibrium, with floorspace supply handled separately based on development event probabilities. It is currently being applied in the development of land use transport interaction models for practical use in several contexts in North America.

The CalSIM model explores the feasibility and benefits of the potential implementation of a statewide integrated land use/economic/ transportation model. It has the ability to assess and depict the interregional effects of major changes to land uses, economics, and transportation on energy, the economy and the environment in a variety of ways.

If implemented, an integrated interregional model could be used to better understand various infrastructure investment proposals and policy options. For example, the model could be used to evaluate economic, land use, environmental, and other potential benefits and impacts of various major transportation investments. It could also be used to assess the potential effects of various types of large-scale policies, programs, and strategies, such as:

  • Costs and benefits of major infrastructure investments
  • Travel between California's regions and counties
  • Habitat and species protection strategies
  • Preservation of agriculture areas
  • Clean Air policies and programs
  • Clean Water Act compliance
  • Economic Development Programs
  • Jobs/Housing Proximity
  • Various housing policies and programs
  • Redevelopment and urban infill strategies
  • Regional job production and job creation programs

CalSIM will be coupled with regional models throughout the state of California. Together they will demonstrate the capability of projecting the aggregate impact of state policies and investments on regions and the interaction of regional policy choices with those statewide efforts thus serving as a national and international example of fully integrated state and regional policy infrastructure investment model. This collaborative work between state and regional government in California has far-reaching applications nationally and will be showcased by the multi-agency Sustainable Communities Partnership currently managed by the federal Department of Transportation (DOT), Housing and Urban Development (HUD), and the Environmental Protection Agency (EPA).

The project is currently funded by the California Department of Transportation , the William & Flora Hewlett Foundation, the Surdna Foundation and the Rockefeller Foundation through 2010

Project Start Date: January 1, 2008
Project End Date: June 30, 2011

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