Urban Spatial Structure and the Potential for Vehicle Miles Traveled Reduction: The Effects of Accessibility to Jobs within and beyond Employment Sub-centers

TL;DR

This study investigates how urban polycentric structures influence vehicle miles traveled, finding that increased access to jobs outside sub-centers significantly reduces household VMT, especially through infill development strategies.

Contribution

It introduces a novel analysis linking job accessibility within a polycentric urban area to VMT reduction, emphasizing the importance of infill development between sub-centers.

Findings

Access to jobs outside sub-centers has the largest negative elasticity (-0.155) with VMT.

Locations with high access to non-centered jobs are often inner ring suburbs near sub-centers.

Infill development between sub-centers may effectively reduce vehicle miles traveled.

Abstract

This research examines the relationship between urban polycentric spatial structure and driving. We identified 46 employment sub-centers in the Los Angeles Combined Statistical Area and calculated access to jobs that are within and beyond these sub-centers. To address potential endogeneity problems, we use access to historically important places and transportation infrastructure in the early 20th century as instrumental variables for job accessibility indices. Our Two-stage Tobit models show that access to jobs is negatively associated with household vehicle miles traveled in this region. Among various accessibility measures, access to jobs outside sub-centers has the largest elasticity (-0.155). We examine the location of places in the top quintile of access to non-centered jobs and find that those locations are often inner ring suburban developments, near the core of the urban area and not far from sub-centers, suggesting that strategies of infill development that fill in the gaps between sub-centers, rather than focusing on already accessible downtowns and large sub-centers, may be the best land use approach to reduce VMT.