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Dear CARB officials:

I am writing to urge the strong consideration of land-use planning
and management as an effective tool to reduce VMT per capita and
thus contribute to California's climate stabilization targets.  I
write this based on many years of experience as a researcher at UC
Berkeley studying these admittedly complex relationships.

I'll make two key points.  (1) Historically, relationships between
travel behavior and land use have been distorted due to
underpricing and resource misallocations -- e.g., free parking,
failure to price externalities, lack of congestion tolls.  In
Europe and elsewhere where fuel and parking charges more closely
reflect true social costs, relationships between urban form and VMT
are much stronger.  Thus combining strategies like Transit Oriented
Development (TOD) with something more akin to social-cost pricing
would reveal that land-use management can play a much more
significant role in reducing CO2 emissions than historically
assumed.  Any scoping plan needs to consider this.  (2) Our
understanding of the elasticities between variables like urban
densities and VMT per capita are based on the low end of the curve.
 As pressures like rising fuel prices (over the long term) prompt
densities to increase, we will be at different places on the demand
curve.  These relationships are historically non-linear.  I believe
at more intermediate levels of prices for fuel and automobile
usage, we will find the influences of factors like urban densities
on transit usage and VMT reductions to be proportionally greater. 
Past empirical studies fail to reflect this.

I have attached a recent study I directed that examines the
influences of density, accessibility, and other factors on VMT per
capita based on experiences across 370 US urbanized areas in the
early 2000s.  The key point is that urban densities significantly
drive down VMT per capita however this benefit can be neutralized
whenever road densities are high.  In short, synergistic benefits
accrue when compact, mixed-use development is accompanied by more
investments in public transit than in roads.  Again, the synergies
from land-use management and "smart transportation" investments, I
believe, are potentially enormous, and this should be reflected in
CARB's draft Scoping Plan. 

Respectfully submitted,
Robert Cervero, Professor
Department of City and Regional Planning
University of California, Berkeley