There's been plenty of anecdotal indications that Americans are driving less, but now the US DOT has provided some data.

Americans drove 20 billion miles less in April than in April of last year.

Treehugger's post on the matter contains a fabulous graphic of the trend, and I can't help but wonder if we're reaching "peak driving," as well as "peak oil." It stands to reason they'd be in the same neighborhood, at least until the two are separated by technology — hydrogen, or electricity powered renewably, or whatever.