|Number registered (thousands)||3,681||4,232||4,374||4,593||4,487||4,481||4,370||4,408||4,906||5,024||5,266||5,293||5,735||5,763||5,926||5,704||5,651|
|Fuel consumed (million gallons)||3,968||5,420||6,923||7,399||8,357||8,172||8,237||8,488||9,032||9,216||9,409||9,576||6,817||9,372||9,563||R9,667||10,305|
|Average miles traveled per vehicle (thousands)||7.4||8.2||9.1||9.9||11.6||11.8||12.3||12.9||12.5||12.5||12.2||12.6||11.9||12.2||11.9||12.7||13.4|
|Average miles traveled per gallon||6.8||6.4||5.7||6.1||6.2||6.5||6.5||6.7||6.8||6.8||6.8||7.0||10.0||7.5||7.4||R7.5||7.4|
|Average fuel consumed per vehicle (gallons)||1,078||1,281||1,583||1,611||1,862||1,824||1,885||1,926||1,841||1,835||1,787||1,809||1,189||1,626||1,614||R1,695||1,824|
KEY: R = revised.
a Beginning in 1998, the Federal Highway Administration (FHWA) used the Census Bureau's 1997 Vehicle Inventory and Use Survey (VIUS) for its baseline estimate of single-unit 2-axle 6-tire or more trucks. Prior to 1998, the FHWA used the Census Bureau's 1992 Transportation Inventory and Use Survey (TIUS) for its baseline estimates. Therefore, post-1997 data may not be comparable to 1997 and earlier years.
NOTES: In 1995, the U.S. Department of Transportation, Federal Highway Administration revised its vehicle categories beginning with 1993 data to include passenger cars, other 2-axle 4-tire vehicles, single-unit 2-axle 6-tire or more trucks, and combination trucks. Single-unit 2-axle 6-tire or more trucks are on a single frame with at least 2 axles and 6 tires. Pre-1993 data have been reassigned to the most appropriate category.
SOURCES: 1970-94: U.S. Department of Transportation, Federal Highway Administration, Highway Statistics Summary to 1995, FHWA-PL-97-009 (Washington, DC: July 1997), table VM-201A.
1995-2002: Ibid., Highway Statistics (Washington, DC: Annual issues), table VM-1.