The latest numbers are for April, when gas prices were considerably higher than they are now. From the Department of Transportion:

Travel on all roads and streets changed by -0.4% (-1.0 billion vehicle miles) for April 2012 as compared with April 2011. Travel for the month is estimated to be 247.2 billion vehicle miles.Cumulative Travel for 2012 changed by +0.9% (8.6 billion vehicle miles). The Cumulative estimate for the year is 939.4 billion vehicle miles of travel.

So we’re slightly ahead of last year’s pace, but that’s still well below the historical trend line, which remained pretty constant for decades — until 2007. Check out this graph from Calculated Risk:

With the population increasing and with GDP growing for the last three years, it’s hard not to think that we might be seeing some sort of fundamental change in Americans’ driving habits.

But it looks like that hypothesis is going to get a tough test in the next few months, as gas prices continue falling.

Here’s the latest from GasBuddy.com.

I’ll be sure to follow this.

By the way, the decline in driving has certainly not been uniform across the country. Here’s DOT’s April map, which shows a particularly steep year-over-year decline in VMT here in the South:

It seems that the concerns and the resulting lack of demand might have helped push crude prices down, which in turn suggests that gas prices might be at or very near their peaks.

If you click to make the chart below stretch back to 2008, you can see that both crude prices and pump prices are below their 2008 peaks. There seems to be compelling evidence that the economic drag from increased gas prices will be limited as long as pump prices stay below that 2008 peak.

Of course, gas prices are a huge issue, and the longterm forecast will be for higher and higher prices, even if the U.S. continues to drill more of its own oil. Oil prices are determined largely by a world market. Increasing demand plus the possibility of political instability will be with us for a long time.

Here’s the latest from GasBuddy.com.