Program Area(s):
Date: May 1, 2021
Author(s): Hao Ding, Brian D. Taylor
Abstract
Traffic impact analysis (TIA), which estimates the traffic impacts of proposed land development, tends to bias against higher density developments in urban areas where traffic is often congested and travel alternatives plentiful. This has important implications for housing supply and affordability, suburban sprawl, and private vehicle dependence. We examine the understudied implication of TIA on housing by drawing on empirical evidence from distinct bodies of research in the transportation and land use planning literatures to describe the mechanisms through which TIA may affect housing market conditions. We conclude that TIAs likely have negative effects on urban housing production and affordability.
About the Project
For decades evaluation of the benefits and costs of new- or re- development in urban areas has centered on the effects of development on nearby traffic flows. Historically, and in most states outside of California, the level-of-service (LOS) scale has been used to approve or disapprove commercial developments. The logic of such an evaluation model is that smooth traffic flows are a primary goal of urban areas, which has the effect of discouraging the sorts of densely developed places that are more easily accessed by foot, bike, shared mobility, and public transit. To overcome the traffic flow focus of traffic impact analyses, the California legislature passed SB 743 in 2013, which mandated a change in the way that transportation impacts are analyzed under CEQA. New CEQA Guidelines were created to replace LOS with a new focus on how proposed developments affect vehicle miles of travel (VMT). This translational project will build on prior research, as well as the burgeoning literature on operationalizing access into transportation planning and engineering to develop and test some new analytical tools to evaluate the access impacts of developments.