The Evaluation of Transportation and Land Use Plans Using Linked Economic and GIS Models

U.S. law requires consistent land use and transportation plans for metropolitan regions and the evaluation of economic efficiency for projects and plans. Policies being examined for reducing travel demand include land use policies. The Clean Air Act regulations require the proper simulation of latent demand in travel modeling for conformity analysis. Current models in use by regional agencies in the U.S. cannot represent the interactions of land use and transport systems in an economically rigorous way and cannot project changes in economic efficiency (locational and traveler surplus). Regional travel demand models in use in the U.S. can represent latent demand as it affects trip distribution, but cannot represent latent demand for auto ownership and for trip generation. Integrated urban models do exist that can perform all of these functions, for regions and for states. We describe a modeling project that applies such a model to an urban region in California and also makes use of GIS to project environmental impacts of scenarios. This set of models may be of use for regional and national planning in Slovakia.