  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.
