I had a big long post written about the why and how of the gas tax in the USA, and the economics of consumer preference, the history of American car design, and the implications of the historic price of fuel on car design, penetration of auto use, and the effect of all that on urban planning.<p>It was too long, and I fear it might be boring. So, to summarize: due to historic accident, Americans like big cars. Moreover, no matter what cars they might prefer, ownership of a car is an economic necessity for most Americans-again, historic accident. Those Americans are also not very well off, at least by northern-Europe standards, so money for gas is a big line-item in the family budget. A regressive tax increase on fuel would be clearly felt &amp;&amp; very unwelcome, even though many if not most could see the logic behind it.