According to the League of American Bicyclists, San Francisco ranks as the no. 4 U.S. city with the greenest commuters. Not including those who drive to work, San Francisco has the highest number of commuters who take transit, followed by walking and biking. San Francisco does outpace the three front runners-- New York, DC and Boston-- in bike commuters. Overall, 49.6 percent of San Francisco's commuters bike, walk or take transit. Like most other cities, the majority of San Francisco's commuters drive to work. When considered by state instead of metro, unsurprisingly District of Columbia ranks as the greenest. The state of California doesn't even rank in the top 10 greenest states. ...