Here’s an interesting factoid from the Transportation Research Board’s new Commuting in America study: of all the metropolitan areas the study looked at, Seattle posted the largest percentage decline in drive-alone commuting from 1990 to 2000. It was a small drop—just 1.5 percent—but it bucked the national trend. Portland also showed a slight decline, along with San Francisco, Phoenix, and Atlanta; and four other cities, including Los Angeles, Sacramento, Dallas and Las Vegas, held steady.

I don’t know what to make of this, exactly. I know from our past work on sprawl that Portland, Seattle, and Phoenix (yes, Phoenix) actually grew more compact over the decade, with a larger share of people living at transit-friendly densities in 2000 than in 1990. The same happened in Sacramento and Las Vegas, and I suspect in San Francisco and Los Angeles too.

But I doubt it happened in Atlanta. Everything I’ve read about the city suggests that greater Atlanta went through a sprawl boom, and a net decline in urban and suburban density, during the 1990s. I haven’t run the numbers, unfortunately; but the other southeastern cities that we studied, Nashville, TN and Charlotte, NC, saw a mind-boggling increase in sprawl.

So I’m not quite sure what accounts for Seattle and Portland’s relative success in trimming drive-alone commuting over the 1990s. Good records in fighting sprawl may be part of the explanation; but given Atlanta’s similar declines in drive-alone commuting, it seems like a city can still notch some progress in commuting trends even if its land use patterns are going in the wrong direction.