New data showing further declines in the number of miles Americans are driving is proof that the country needs means, other than the gas tax, to finance the nation's transportation infrastructure, according to the U.S. Department of Transportation.


Americans drove 9.6 billion fewer vehicle-miles traveled (VMT) in May 2008 than in May 2007, according to the Federal Highway Administration data. This is the largest drop in VMT for any May, which typically reflects increased traffic due to Memorial Day vacations and the beginning of summer, and is the third-largest monthly drop in the 66 years such data have been recorded. Three of the largest single-month declines - each topping 9 billion miles - have occurred since December.

VMT on all public roads for May 2008 fell 3.7 percent as compared with May 2007 travel, marking a decline of 29.8 billion miles traveled in the first five months of 2008 than the same period a year earlier. This continues a seven-month trend that amounts to 40.5 billion fewer miles traveled between November 2007 and May 2008 than the same period a year before, she said.

"By driving less and using more fuel-efficient vehicles, Americans are showing us that the highways of tomorrow cannot be supported solely by the federal gas tax," said U.S. Secretary of Transportation Mary E. Peters. "We must embrace more sustainable funding sources for highways and bridges through more sustainable and effective ways such as congestion pricing and private activity bonds."

As Americans drive less and rely increasingly on mass transit, carpooling or other options, the federal Highway Trust Fund receives less revenue from gasoline and diesel sales, 18.4 cents per gallon and 24.4 cents per gallon, respectively.

"Less driving means less money for the Highway Trust Fund," said Acting Federal Highway Administrator Jim Ray. "The status quo cannot and will not work in the 21st century."