Brian hit the issue almost a year ago, but Jordan Weissmann at the Atlantic recently re-focused attention on the problem of funding U.S. highways with fuel taxes:

Since back in the Eisenhower era, the federal government has maintained a Highway Trust Fund, paid for mostly by taxes on fuel, that helps cover the repair and construction of our country’s roads, bridges, and mass transit. The idea was that drivers themselves should bear some of the cost the roads they used. Unfortunately, Congress hasn’t raised the gas tax since 1993. Since then, inflation has eaten away at least a third of its value…[and] two new challenges [have] emerged. First, Americans started caring about the fuel efficiency again, as skyrocketing oil prices ended the era of gas-guzzling SUVs. Then the recession struck, and penny-pinching drivers logged fewer miles to save on gas.

The upshot, of course, is that

less money is flowing into the Highway Trust Fund, which is now facing potential insolvency in 2013, according to the Congressional Budget Office.

I guess it’s good that fuel efficiency gains are having an impact?  (Ah, unintended consequences.)  Looks like we’re headed into a world where cars will have to start paying by the mile–or the highways are going to get a lot worse.