Higher Gas Prices, less driving
Americans drove 42 billion fewer miles during the first 6 months of 2008 compared to the same period in 2007. The break up was:
Month Drop in miles (billion) Jan 3.6 Feb 1.0 Mar 11.1 Apr 3.9 May 10.2 Jun 12.2
(figures from USA Today Aug 22)
As you can see as the gas prices rose over the year, the driving dropped tremendously. Personally I have always felt that there is a strong case in the US for a strong mass transit system based on railway, but somehow the oil lobby has held this entire country to ransom!