View source for Interstate Highway System

[[Image:Map of current Interstates.svg|400px|thumb|right|A [[map]] showing the interstate highways. Green shows freeways still under [[construction]].]]
The '''Interstate Highway System''' is a [[system]] of [[freeway]]s in the [[United States]]. It was first designed by [[Dwight D. Eisenhower]] in the 1950s. The [[Federal Aid Highway Act of 1956]] was used to pay for construction.<ref>{{cite web|url=http://www.history.com/topics/interstate-highway-system |title=The Interstate Highway System |publisher=History |accessdate=23 July 2014}}</ref> It was mostly built from the 1950s through the 1960s, but more freeways were built later. It is now about 47,000 miles long. Some interstates have [[toll]]s, but most do not.<ref name="Interstate Guide">{{cite web |url=http://www.interstate-guide.com/interstate.html |title=All About Interstate Highways |website=AARoads Interstate Guide |date=29 July 2008 |accessdate=23 July 2014 |archive-date=30 June 2014 |archive-url=https://web.archive.org/web/20140630071214/http://www.interstate-guide.com/interstate.html |url-status=dead }}</ref> Most interstates have [[rest area]]s every few dozen miles.
== What is needed ==
To be an Interstate Highway, there cannot be any [[traffic light|stoplights]]. To get on or off the freeway, an [[interchange (road)|interchange]] is needed. The [[speed limit]] is usually at least 55 miles per hour. It must have at least two [[lane]]s going each way. The lanes must be at least 12 feet wide.<ref name="Interstate Guide" /> There has to be a [[median (road)|median]] or [[barrier]] between cars going different directions.
== Numbering ==
North-south interstates have odd numbers. The numbers go up from west to east. East-west interstates have even numbers. The numbers go up from south to north. One and two [[digit]] freeways go long distances. Three digit freeways go into or around cities.<ref name="Interstate Guide" /> Freeways that go into cites are called '''spur routes''' and start with an odd number. Freeways that go around cities are called '''loop routes''' and start with an even number. The last two digits in a spur or a loop route are the same as the freeway it started from.

== Interstate Highway System Media ==
<gallery widths='160px' heights='100%' mode='traditional' caption=''>
File:MUTCD M1-10a.svg|900 mm by 900 mm (36 in by 36 in) Eisenhower Interstate System sign, made to the specifications of the 2004 edition of Standard Highway Signs (sign M1-10a). Uses the Roadgeek 2005 fonts. (United States law does not permit the copyrighting of typeface designs, and the fonts are meant to be copies of a U.S. Government-produced work anyway.) Colors are from 

File:Project for the Development of National Highways of the United States.png|the Pershing Map

File:FDR Proposed Highways.jpg|FDR's hand-drawn map from 1938

File:National Highway Program - National System of Interstate Highways - Rural Status of Improvement, 1965.png|1955 map: The planned status of US Highways in 1965, as a result of the developing Interstate Highway System

File:STEEL RODS, MADE FROM SHREDDED AUTOS, ARE BEING USED FOR REINFORCEMENT IN THIS SECTION OF I-55, NORTH OF DURANT. IT... - NARA - 546265.jpg|[[Interstate 55 in Mississippi|I‑55]] under construction in [[Mississippi]] in May 1972

File:CA 58 I5 FHWA 1957 5776 14.jpg|1957 aerial photograph showing a recently constructed interchange on I-5 in [[Glendale, California]]

File:Eisenhower Interstate System sign.jpg|Commemorative sign introduced in 1993. The system was established during Dwight D. Eisenhower's presidency, and the five stars commemorate his rank as [[General of the Army (United States)|General of the Army]] during World War II.

File:Interstate_81_elevated_syracuse_E_Genesee_St.jpg|The fervor of [[urban renewal]] led to the routing of [[Interstate 81 in New York|Interstate 81]] through the middle of [[Syracuse, New York|Syracuse's]] 15th Ward in the 1960s. The viaduct is now slated for demolition.

File:2019-07-15 11 10 50 View south along Interstate 95 from the overpass for Maryland State Route 175 (Waterloo Road-Rouse Parkway) in Columbia, Howard County, Maryland.jpg|[[Interstate 95 in Maryland|I-95]] in [[Columbia, Maryland]], built to modern standards.

File:Interstate_5_in_the_Central_Valley.jpg|A rural stretch of [[Interstate 5 in California|I-5]] in California; two lanes in each direction are separated by a large grassy [[central reservation|median]] and cross-traffic is limited to [[grade separation]]s such as this overpass.
</gallery>
== Related pages ==
*[[List of Interstate Highways]]
*[[List of auxiliary Interstate Highways]]
== References ==
{{reflist}}

{{interstates}}

{{transport-stub}}

[[Category:Interstate Highways| ]]