Supply an demand is still a law that is dependent on demand.

There are plenty of ways to cut gas use but Americans are largely unwilling.

People seem more concerned about the appearance of commuting via mass transit, car pool or even a 50cc scooter (some get upwards of 76 miles per gallon) than what impact such changes would make on the amount of fuel actually consumed. This isn't a case of developing new technologies.. it is a case of being willing to take responsibility for our own situation, cutting back, and making use of existing technologies.