|Other 2-axle, 4-tire vehiclesa,R||225,613||520,774||999,754||1,338,135||1,432,782|
a In July 1997, the U.S. Department of Transportation, Federal Highway Administration, reassigned some vehicle from "passenger car" to "other 2-axle, 4-tire."
b Includes municipally owned transit, commercial, federal, and school buses.
c Includes demand responsive, ferry boat, and other transit not specified; 1980 data include ferry boat and "other transit" only.
d Includes light and heavy rail only.
e Fiscal year data. Amtrak began operations in 1971.
Sources: U.S. Department of Transportation (USDOT), Bureau of Transportation Statistics (BTS), National Transportation Statistics 2000 (Washington, DC: In press), table 129; USDOT, BTS, Office of Airline Information, Air Carrier Traffic Statistics (Washington, DC: 2000); USDOT, Federal Highway Administration, Highway Statistics 1999 (Washington, DC: 2000); and Association of American Railroads, Railroad Facts,1999 (Washington, DC: 2000).