Although hybrid gas-electric vehicles—including the Toyota Prius and the Honda Insight and a version of the Civic—are certainly becoming more common, they’re still a rarity on the roads: in 2003 there were less than 44,000 registered in the entire U.S.

By contrast, there are about 230,000,000 non-hybrid cars and trucks in the US.

Virginia and Maryland have the most hybrid cars per capita—with 4.5 and 3.4 hybrid vehicles for every 10,000 residents. Washington and Oregon rank fourth and fifth, with about 3 hybrids per 10,000 people.

Hybrids should see a boost in coming years, with a new Ford hybrid SUV that gets 40 miles per gallon in city driving. But an even more effective fuel-saver is to live in a neighborhood where you don’t need to drive much. That’s one reason that residents of denser European cities use about a 40 percent of the highway fuels that Northwesterners do—it’s not just that they’re driving better cars, but also that they’ve arranged their cities so that the car is a convenience, not an absolute necessity. We could aim to do the same.

Update:this likely explains why Virginia ranks highly in hybrid ownership—if you drive a hybrid, you get to drive solo in the HOV lanes.