Which states use the least gasoline?  Which ones have the best gas-conservation trends? Probably not who you’d think, at least for the latter question.

Based on Federal Highway Administration data covering 2001 through 2003, residents of New York State use the least gasoline, person for person, of any U.S. state: about 0.8 gallons per person per day, vs. the national average of 1.2 gallons per person. That’s to be expected: New York City–which makes up a sizable chunk of the state’s population–is among the densest cities in the country, which allows many of its residents to get by perfectly well without cars, except for the occasional taxicab.

The runners-up to New York were: Hawaii–with high priced gas and surprisingly dense Honolulu–at .9 gallons per person per day; Rhode Island–dominated by urban Providence–at one daily gallon per capita; and Illinois–which has a significant share of residents in urban Chicago and its dense inner suburbs–with 1.1 gallons. Oregon, Washington, and Idaho rank 8th, 12th, and 17th, respectively, in per capita gas consumption; but all three states are close to the national average.

The states that use the most gas are either predominantly rural, have particularly sprawling cities, or both. Wyoming residents use the most gasoline (1.8 gallons per person per day), followed by residents of Georgia, South Carolina, and Vermont at about 1.5 gallons per capita.

Now, for the trend lines — over the long term, which states are going in the right direction? If you guessed Nevada, you hit the jackpot.

Today, Nevada residents use about 1.2 gallons of gas per person per day — close to the national average, but nearly a third less than they did in 1976-1978, the peak period for gas consumption in the state (and, coincidentally, for the entire U.S. as well).  In terms of reductions in gas consumption, no other state in the same league as Nevada.

Nevada's gas consumptionThe other states that saw significant reductions in gas consumption per capita were predominantly western:  New Mexico (-20%), Oregon (-19%), and Wyoming, Oklahoma, and Utah (-16%).

The big gas consumption increases, perhaps surprisingly, were concentrated on the northern half of the Eastern seaboard:  New Hampshire, Vermont, New Jersey, Maine, and Massachusetts make up 5 of the top 7 gas consumption gainers.  (Mississippi and South Carolina rounded out the top 7.)

In some ways, these gas trends are in tune with our recent sprawl research, which found that arid western cities are sprawling much less than cities where water is abundant. Apparently, desert is a pretty powerful growth boundary. Las Vegas was the least sprawling of 15 U.S. cities we studied (although it isn’t as compact as Vancouver, BC). Other dense cities included Salt Lake City, Phoenix, and Denver. Growth management laws in Portland, OR did very well at preventing the loss of farmland and open space to suburban development; but the city, after 30 years of growth management laws, is only now approaching the levels of density that are common in more arid parts of the western US.

In some ways these results come as a surprise; nobody thinks of Phoenix or Las Vegas as smart growth meccas.  But the gasoline data–which shows that arid states (plus Oregon) are faring best at reducing gas consumption–are certainly consistent with the picture that emerges from sprawl research–which shows that arid cities are sprawling less, meaning that their residents are able to drive less as well.

The lesson I draw from all of this is pretty simple: if you want to reduce gas consumption, creating more compact cities seems like a very effective long-term strategy.