U.S. Department of Energy - Energy Efficiency and Renewable Energy

Vehicle Technologies Office

Fact #436: August 7, 2006
Interstate Travel

This year the Federal Highway Administration is celebrating the 50th anniversary of the Interstate System, which was begun in 1956. The Interstate system is currently used for about one quarter of all vehicle miles of travel. The Interstate system's share of travel rose rapidly in the 1960's and 1970's as the completed Interstates provided links of connectivity across the nation for goods and for people.

Share of Interstate Travel, 1957-2004
Graph showing the relationship between vehicle miles traveled on an interstate compared to all travel. Currently interstate travel is about one quarter of all vehicle miles traveled. For more detailed information, see the table below.
Other Interstate Facts:
Number of Interstate miles 46,726 miles of interstate
Longest Interstate Route I-90 from Seattle, WA to Boston, MA
3,020.54 miles
Shortest Interstate Route I-97 from Annapolis to Baltimore, MD
17.62 miles
State with the most interstate mileage Texas
3,233.45 miles
State with the most interstate routes New York
29 routes
Interstate which traverses the most States I-95 which goes through 16 States from Florida to Maine

Source: U.S. Department of Transportation, Federal Highway Administration

Supporting Information

Share of Interstate Travel, 1957-2004
Year Interstate Miles of Travel
(million miles)		 All Miles of Travel
(million miles)		 Share of Interstate Travel Year Interstate Miles of Travel
(million miles)		 All Miles of Travel
(million miles)		 Share of Interstate Travel
1957 6,806 645,004 1.1% 1981 305,783 1,555,308 19.7%
1958 12,922 664,653 1.9% 1982 318,425 1,595,010 20.0%
1959 19,997 700,480 2.9% 1983 337,720 1,652,788 20.4%
1960 26,778 718,762 3.7% 1984 353,443 1,720,269 20.5%
1961 34,233 737,421 4.6% 1985 370,545 1,774,826 20.9%
1962 44,181 766,734 5.8% 1986 391,515 1,834,872 21.3%
1963 55,210 805,249 6.9% 1987 415,329 1,921,204 21.6%
1964 67,428 846,298 8.0% 1988 440,010 2,025,962 21.7%
1965 80,690 887,812 9.1% 1989 461,820 2,096,487 22.0%
1966 99,314 925,899 10.7% 1990 479,074 2,144,362 22.3%
1967 111,164 964,005 11.5% 1991 490,336 2,172,050 22.6%
1968 126,273 1,015,869 12.4% 1992 508,822 2,247,151 22.6%
1969 45,016 1,061,791 13.7% 1993 525,707 2,296,378 22.9%
1970 161,048 1,109,724 14.5% 1994 546,145 2,357,588 23.2%
1971 179,659 1,178,811 15.2% 1995 565,319 2,422,696 23.3%
1972 199,580 1,259,786 15.8% 1996 584,144 2,485,848 23.5%
1973 215,547 1,313,110 16.4% 1997 601,656 2,561,695 23.5%
1974 213,925 1,280,544 16.7% 1998 626,142 2,631,522 23.8%
1975 230,212 1,327,664 17.3% 1999 643,425 2,691,056 23.9%
1976 250,583 1,402,380 17.9% 2000 662,070 2,746,925 24.1%
1977 267,788 1,467,027 18.3% 2001 673,602 2,797,287 24.1%
1978 292,918 1,544,704 19.0% 2002 689,817 2,855,508 24.2%
1979 293,049 1,529,133 19.2% 2003 702,581 2,890,450 24.3%
1980 296,326 1,527,295 19.4% 2004 721,381 2,962,513 24.4%

Source: U.S. Department of Transportation, Federal Highway Administration, Highway Statistics 2004, and previous annual editions.

 

Return to 2006 Facts of the Week