It’s interesting to me that so many people find the idea of a VMT tax to be clearly ridiculous. At present, federal gas tax revenues are insufficient to cover spending on highways (to say nothing of all transportation needs), and spending on transportation is insufficient to cover critical needs (to say nothing of desirable expansions). Meanwhile, vehicle efficiencies are likely to increase substantially in the decade to come. As hybrids and hybrid electric plug-ins become more common (and as other alternatives to travel by gas-powered engine — transit, biking, etc — become more common) gasoline demand will become more elastic. Governments looking to wring more revenue out of the gas tax will have an increasingly difficult time doing so. I strongly support an increase in the gas tax, but as a means to adequately fund transportation spending, its days are numbered. Now is the time to begin thinking about how to fund transportation ten and twenty years down the road.

I think the place to start is with congestion pricing, although I’d also like to see a share of revenues from carbon pricing devoted to transportation. But I don’t think it’s absurd to put a VMT tax on the table. Policy merits will be balanced in Washington against political acceptability, and clearly there are legislators who feel that the idea of a VMT tax — of paying for the miles you drive on public roads — might make sense to drivers. I don’t think that’s nuts.

I know that many people feel that the civil liberties issue is a dealbreaker, but I have a hard time believing that. These days, people don’t blink at the prospect of unwarranted domestic surveillance, they walk around with multiple mobile devices, and they live half their lives online. A gizmo that keeps track of how far they’ve driven isn’t likely to phase most Americans.