Every few years, the Federal Highway Administration conducts a major survey called the NHTS to find out how Americans travel. The 2009 survey collected questionaires from more than 150,000 different households. Some of the results from that survey are now available in several formats.
The complete dataset is about 500 megabytes in ASCII format. Much briefer are a number of frequently-asked for table, including tables showing daily trips and miles by household income, mode and purpose, and other variables. You can also design your own table, though many useful variables in the survey, such as person miles of travel, are not (yet?) included in the design-your-own tables.
The first thing that must be noted is that the 150,000 households surveyed were not an accurate cross-section of the nation. For example, they surveyed one household for every 1,000 people in the Dallas-Ft. Worth metropolitan area, but only one for every 11,000 people in the Chicago metropolitan area, and (apparently) no one at all in the Atlanta metro area. Further, though more than two-thirds of Americans live in urban areas of 50,000 people or more, only about 61 percent of the surveys came from such areas.
