Del, I agree 100% on the lets stop doing the stuff we don't need--I don't even care how we arrive at the conclusion it that is the outcome.
I do know almost every major city I visited recently, Tampa, Sacremanto, Altanta, DMV, New York, Charlotte is buried in traffic. In places like Tampa, everyone drives humongous vehicles all by themselves. If we changed our collective behavior I think the population would not be much of a factor.