Using data collected via the American Community Survey, that sorta sub-census that determines how federal and state dollars are distributed every year, the Transport Politic took the largest 30 U.S. cities and tabulated the changes in their commuting habits from 2000 to 2009.Some of the results are startling; some are hardly surprising. First, Baltimore is second among those cities--to Portland, Ore., naturally--for gains in cycling as overall share of commuting trips. The exact gain is 200.6 percent to Portland's 230 percent. Which is really not too shabby, and should probably be taken as the result of a combination of things, including the city generally getting safer, an influx of young people with different habits, and the City of Baltimore taking initiative on improving things for bikers in the city.Now for the bad news: That 200 percent gain doesn't add up to much. Cycling still only accounts for 1 percent of all commutes in Baltimore.And now for even more bad news. More people in Baltimore are driving. The biggest loss in any particular mode of transportation comes in mass transit, with a disappointing 12.7 percent decline. That said, we're still in the upper third as far as transit as a total share, with 17 percent of commuters getting around on buses or trains. And, in fact, most cities did decline in transit use with the very notable exception of Los Angeles, which has put sustained and concentrated effort into improving its transit system in the past decade. Another exception is Washington D.C., which boasts one of the best subway networks in the world, with an increase of 12 percent.