(Georgia Institute of Technology, 2012-11-15)
Sundquist, Eric William
Reducing vehicle-miles traveled (VMT) has become an important goal for improving environmental outcomes and reducing the costs of travel and infrastructure. One way to accomplish such reductions could be to enact policies that foster more compact development. However, while it is accepted that compact development is associated with lower VMT, there remain disagreements about the efficacy of this policy lever. One issue casting doubt on the power of compact development relates to travelers' exposure to density. A conventional view holds that many travelers' neighborhoods are "locked in place" because change in established neighborhoods is slow. Additionally, conventional explanations of the effect of denser development focus on travelers' own neighborhoods, or on the metro area as a whole, failing to isolate the effect of densifying nodes near, but outside of, the travelers' neighborhoods. This study employs housing and travel data from the Seattle-Tacoma, Wash., where policies aimed at encouraging compact development have been in place since the mid-1990s. Findings suggest that 1) in established neighborhood, incremental change often results in exposure to substantially higher density, and 2) that even where localized density is constant, increases in density at intentional nodes or other areas near, but outside of, a traveler's own neighborhood, has a strong effect on VMT. The findings tend to undermine some of the key doubts about using land use as a policy lever for VMT reduction.