Released in July 2002, this 431-page document prepared by the United States Bureau of Transportation Statistics contains almost every piece of aggregate data on transportation imaginable. While going through the entire document may be a challenge, the report is divided into more readily digestible sections such as Transportation System, Transportation Safety, and Transportation and the Economy....

The US Department of Transportation's Bureau of Transportation Statistics provides Transportation Statistics Annual Report (TSAR), a companion to NTS, in Adobe Acrobat (.pdf) format, from 1994 to the present at this time. Transportation in the United States: A Review, summarizing these four reports, is also available.