Here’s the word from the US Department of Transportation:

[Vehicle travel] 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.

US VMT trendsSo it’s official:  high gas prices (coupled with a slack economy) are encouraging us to drive less. And if you look at the chart to the right, the recent downturn comes after a fairly long period of slow growth in vehicle travel.  It looks like the gradual rise in gas prices has been tempering the growth of driving since at least 2005.

I wouldn’t be surprised to find that total gas consumption has fallen even more steeply than the number of miles driven.  After all, SUV sales are down; sales of efficient cars are up; highway speeds are slowing slightly; congestion is down (because fewer cars are on the road); and there’s anecdotal evidence that people are choosing the more efficient car when they have more than one vehicle in the driveway.  All of these factors tend to decrease gasoline consumption, above and beyond the decline in vehicle miles traveled.

Of course, the DOT responds to the news by…calling for more money for roads!

“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.”

That’s right: we’re driving less, gas costs are through the roof, and people are turning to transit in record numbers.  But according to the DOT, the real problem is that the Highway Trust Fund is running out of cash.  (How on earth are we going to pay for all those new roads that people can’t afford to drive on?)