I currently spend more than twice the money on a monthly rail pass than I would on gas. The city into which I commute deliberately (not kidding) limits the amount of non-resident parking in an attempt to reduce traffic. I figure that half the traffic they do have is circling the block looking for a place to park.
I think the whole price-at-the-pump begs the question: "how much would it cost for gas if we weren't giving scores of $Billions in subsidies to oil companies, and paying hundreds of $Billions for worldwide military security for the oil machine."
My answer: "None, we'd have alternatives."