One of the simplest ways to measure our dependence on cars is to look at the share of commuters in a given city who get to work in a private vehicle. These are the people who rely on automobiles as part of their everyday travel patterns. They're people who live too far from work to walk there, who may prefer not to take transit, or who simply have no other options. They're the commuters for whom communities must widen highways for rush-hour capacity and build out parking garages for downtown businesses.
Over the last decade, however, a new report from the U.S. PIRG Education Fund and the Frontier Group finds that the share of workers who get to work by private car declined in 99 of America's 100 largest urbanized areas (by the Census Bureau's definition, this is a densely populated geography often larger than a single city but smaller than a metropolitan area). The lone outlier was New Orleans, which has been an outlier in many ways since Hurricane Katrina.
Benjamin Davis and Phineas Baxandall calculated this using "journey to work" data from the 2007-2011 American Community Survey, comparing it to the year 2000. The results suggest that the biggest declines in car commuters have come in the New York-Newark area; Washington, D.C.; Austin, Texas; and Poughkeepsie-Newburgh, N.Y. In all four urban areas, the share of workers commuting by private vehicle has dropped by 4 percent or more: