Don't need to bulldoze much of anything to do something though. The inefficiency of buildings is a tiny part of the problem, especially in temperate climates; more mixed use zoning, and the relaxing of single family dwelling zoning, will have a dramatic impact on excess travel.

Transport accounts for basically a third of U.S. energy use, though it has been hardly growing over the last few years, which is a good start.

The most efficient car, bus, or train, is the one that you didn't ride.