Excel | CSV
SOURCES: 1991-1995: U.S. Department of Transportation, Federal Highway Administration, Highway Statistics Summary to 1995 (Washington, DC: 1997), tables MV-201 and VM201a. 1996-1997:____. Highway Statistics 1997 (Washington, DC: 1998), table VM-1. 1998-1999:____. Highway Statistics 1999 (Washington, DC: 2000), table VM-1.