Interstate Highway System

filed under | geography | cars


The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly called the Interstate Highway System (or simply, the Interstate System), is a network of limited-access highways (also called freeways or expressways) in the United States that is named for President Dwight D. Eisenhower, who championed its formation. The entire system, as of 2006[update], has a total length of 46,876 miles (75,440 km), making it both the largest highway system in the world and the largest public works project in history. The Interstate Highway System is a subsystem of the National Highway System. While Interstate Highways usually receive substantial federal funding (90% federal and 10% state) and comply with federal standards, they are owned, built, and operated by the states or toll authorities. For example, the original Woodrow Wilson Bridge (part of Interstate 95/495), was maintained by the federal government; its new span is now jointly owned and maintained by the state of Maryland and the Commonwealth of Virginia. There are also other Interstate Highways within the District of Columbia, which is federal territory. This freeway system serves nearly all major U.S. cities, with many Interstates passing through downtown areas. The distribution of virtually all goods and services involves Interstate Highways at some point. The numbering scheme for the Interstate Highway System was developed in 1957 by the American Association of State Highway and Transportation Officials (AASHTO). The association's present numbering policy dates back to August 10, 1973.[29] Within the continental United States, primary Interstates – also called main line Interstates or two-digit Interstates – are assigned numbers less than 100. In the numbering scheme, west–east highways are assigned even numbers and south–north highways are assigned odd numbers. Odd route numbers increase from west to east, and even-numbered routes increase from south to north, though there are exceptions to both principles in several locations. As one of the components of the National Highway System, Interstate Highways improve the mobility of military troops to and from airports, seaports, rail terminals, and other military bases. Interstate Highways also connect to other roads that are a part of the Strategic Highway Network, a system of roads identified as critical to the U.S. Department of Defense. A widespread urban legend states that one out of every five miles of the Interstate Highway System must be built straight and flat so as to be usable by aircraft during times of war. Contrary to popular lore, Interstate Highways are not designed to serve as airstrips. [READ THE REST OF THIS ARTICLE] is not affiliated with or endorsed by wikipedia. wikipedia and the wikipedia globe are registered trademarks of
article content reproduced in compliance with wikipedia's copyright policy and gnu free documentation license
view our privacy policy and terms of service here