Coupled land use and transportation models: The LEAM/transeval experience in St Louis, MO

Although a relatively new science, simulated alternative patterns of future land-use change can be a valuable tool in assisting stakeholders in a region grapple with different and competing public policy and public investment choices. Transportation engineers on the other hand, have used modeling techniques to test transportation investments since the 1950s. When land use and travel demand are jointly modeled, the resultant simulations are more robust, more effectively informing choices - especially those made with regard to transportation policies and investments. In this paper, we seek to advance inquiry into connecting land-use and travel-demand simulation models through a qualitative assessment of the change in land-use and travel demand outcomes as a result of combining two models. We describe the land use (LEAM) and travel demand (TransEval) models for the St. Louis region and how they were loosely coupled. We then compare land use and travel demand simulations with and without coupling so as to isolate the effects of coupling. We conclude with discussion of the implication of these results on planning and potential planning support systems.