Mainstreaming transportation and land use modeling within Oregon DOT

By Chris McCahill
States interested in modeling transportation and land use can now learn from Oregon’s experience building its Statewide Integrated Model (SWIM), thanks to a new study published in the Journal of Transport and Land Use. The model, now used in ODOT’s regular operations, grew out of its decades-long Transportation and Land Use Model Integration Program (TLUMIP), launched in the late 1990s. Several keys to its success were committed staff, a sharp focus on meeting agency needs, and the ability to adapt as those needs changed.
According to the study, the entire modeling program cost ODOT $9.1 million—most of which went toward data development, rather than model-building. It has since proven to be a cost-effective decision-making tool. In 2004, for example, ODOT’s modeling team studied how premature bridge cracking could affect connectivity and economic productivity across the state. Short on money, that information let the agency prioritize its most critical bridges for repair in a $4.3 billion program that spared the state most of the potential impacts.
When the program first launched, an important motivation was the need to evaluate the effects of Oregon’s urban growth boundaries. Over time, its focus shifted toward understanding economic impacts, emissions, and dynamic pricing. The model is used to evaluate the economic impacts of bottlenecks and inadequate pavement and it could be invaluable in understanding the effects of new technologies like autonomous vehicles and TNCs.
Technologically, the program has also shifted considerably. Early on, it focused on microsimulation and even helped incubate other efforts like UrbanSim. As analytical needs evolved, however, the model incorporated a simpler, more aggregate approach and gradually grew more complex. According to the study, the analytical context for the model (the “stories to be told”) always drove the project. Today, it is an exemplar. This long-term process, according to the study, would not have been possible without committed ODOT staff and program managers that stayed active through most of the process.
Chris McCahill is an Associate Researcher at SSTI.