This paper compares four transportation energy conservation strategies using a comprehensive evaluation framework that takes into account how each
strategy affects annual vehicle travel, and therefore mileage-related impacts such as traffic congestion, road and parking facility costs and crash risk. Mileage-related impacts tend to be large in magnitude compared
with energy conservation benefits, so even small changes in total vehicle travel can have a large impact on net benefits. Fuel efficiency standards and some alternative fuels cause vehicle travel to increase. Higher fuel
taxes cause a combination of increased vehicle fuel economy and reduced mileage. Mobility management strategies cause relatively large mileage reductions and so provide the greatest mileage-related benefits.
Conventional evaluation practices often overlook mileage-related impacts and so tend to overvalue strategies that increase vehicle fuel efficiency and undervalue mobility management strategies. Published recently in
"Transport Policy," Volume 12, Issue 2, March 2005, Pages 121-129, (http://authors.elsevier.com/sd/article/S0967070X04000575).

Full paper: http://www.vtpi.org/cafe.pdf