Eighty-six percent of Americans drive to work, but the figures are lower in metropolitan areas such as New York City, San Francisco and Boston. Length of commute, weather, job type and population density all influence how people commute, according to an analysis by University of Maine economics professor Todd Gabe. People who live in drier climates, or who have creative jobs, are more likely to walk, bike or use public transportation to get to work, Gabe found.
http://www.theatlantic.com/national/archive/2011/07/the-geography-of-how-we-get-to-work/240258/
Article courtesy of Smart Growth Onlilne from The Atlantic by Richard Florida