The impact of urban form and gasoline prices on vehicle usage: Evidence from the 2009 National Household Travel Survey

This paper relies on generalized structural equation modeling (SEM) to tease out the relationship between land use, gasoline prices and travel behavior. We analyze data from a Southern California subsample of the 2009 National Household Travel Survey (NHTS), which has a quasi-experimental nature thanks to large exogenous variations in gasoline prices during the administration of the NHTS (March 2008-April 2009). Our joint models of residential urban form, vehicle efficiency choice, and vehicle use account for residential self-selection and endogeneity of vehicle preferences in order to explain vehicle miles traveled (VMT) for both work and non-work trips. Residential urban form is treated as a latent construct that reflects observed variables such as population density, land use diversity and distance to employment centers. We find that in the short run, households drive 0.171% less for non-work trips when gas prices increase by 1%, while work trips are not responsive to gasoline price changes. Moreover, owners of more fuel efficient vehicles tend to be more educated and Asian. In addition, households in lower density neighborhoods are more likely to have a higher income, to be older than 65 and White; these households tend to own more vehicles per driver. Overall, our results underscore the importance of accounting for the nature of trips when estimating the short-term price elasticity of travel.