University of California Transportation Center

Can urban design improve the environment? If communities could be designed to reduce automobile use, then yes. But can urban design influence travel? Surprisingly perhaps, the effects of any specific neighborhood feature on travel behavior at the margin are all but unknown. The policy significance of this issue is reflected in the swelling popularity of the “new urbanism” and other planning strategies employing land use tools to mitigate the environmental impacts of metropolitan development. In addition to asserting that development patterns and densities affect how far, how often, and by what means people travel, urban designers frequently argue that the legibility and shape of the local street pattern play a key role. “Connected” residential blocks are thus associated with less driving by comparison with the circuitous routes of the modern suburban cul-de-sac — chiefly by reducing trip lengths and facilitating pedestrian and transit access. Remarkably, there is little empirical and theoretical support for these claims. This paper provides the first direct tests of these hypotheses within a consistent behavioral framework. An analysis of household travel diary and GIS data for San Diego finds little role for land use in explaining travel behavior, and no evidence that the street network pattern affects either short or long non-work travel decisions. While results may vary in other areas, the empirical argument for using land use as an element of regional air quality or other environmental plans remains to be demonstrated.