Editing Interstate Highway System (section)

{{Short description|Network of freeways in the United States}}
{{Redirect|Interstate|the type of highway|Controlled-access highway|other uses|Interstate (disambiguation)}}
{{Use American English|date=June 2017}}
{{Use mdy dates|date=February 2023}}
{{infobox state highway system
|title= Dwight D. Eisenhower National System of Interstate and Defense Highways
|shields= {{infobox road/shieldmain/USA|type=I|route=80}}{{infobox road/shieldmain/USA|type=BL|route=80}}[[File:MUTCD M1-10a.svg|70px|alt= Eisenhower Interstate System sign]]
|caption= [[Highway shield]]s for Interstate&nbsp;80, Business Loop Interstate&nbsp;80, and the Eisenhower Interstate System
{{Maplink|frame=yes|plain=yes|frame-align=center|frame-width=320|frame-height=240
|type=line|from=Interstate 2.map
|type2=line|from2=Interstate 4.map
|type3=line|from3=Interstate 5.map
|type4=line|from4=Interstate 8.map
|type5=line|from5=Interstate 10.map
|type6=line|from6=Interstate 11.map
|type7=line|from7=Interstate 12.map
|type8=line|from8=Interstate 14.map
|type9=line|from9=Interstate 15.map
|type10=line|from10=Interstate 16.map
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|type12=line|from12=Interstate 19.map
|type13=line|from13=Interstate 20.map
|type14=line|from14=Interstate 22.map
|type15=line|from15=Interstate 24.map
|type16=line|from16=Interstate 25.map
|type17=line|from17=Interstate 26.map
|type18=line|from18=Interstate 27.map
|type19=line|from19=Interstate 29.map
|type20=line|from20=Interstate 30.map
|type21=line|from21=Interstate 35.map
|type22=line|from22=Interstate 37.map
|type23=line|from23=Interstate 39.map
|type24=line|from24=Interstate 40.map
|type25=line|from25=Interstate 41.map
|type26=line|from26=Interstate 42 1.map
|type27=line|from27=Interstate 43.map
|type28=line|from28=Interstate 44.map
|type29=line|from29=Interstate 45.map
|type30=line|from30=Interstate 49 1.map
|type31=line|from31=Interstate 55.map
|type32=line|from32=Interstate 57.map
|type33=line|from33=Interstate 59.map
|type34=line|from34=Interstate 64.map
|type35=line|from35=Interstate 65.map
|type36=line|from36=Interstate 66.map
|type37=line|from37=Interstate 68.map
|type38=line|from38=Interstate 69.map
|type39=line|from39=Interstate 70.map
|type40=line|from40=Interstate 71.map
|type41=line|from41=Interstate 72.map
|type42=line|from42=Interstate 73.map
|type43=line|from43=Interstate 74.map
|type44=line|from44=Interstate 75.map
|type45=line|from45=Interstate 76 (Ohio–New Jersey).map
|type46=line|from46=Interstate 76 (Colorado–Nebraska).map
|type47=line|from47=Interstate 77.map
|type48=line|from48=Interstate 78.map
|type49=line|from49=Interstate 79.map
|type50=line|from50=Interstate 80.map
|type51=line|from51=Interstate 81.map
|type52=line|from52=Interstate 82.map
|type53=line|from53=Interstate 83.map
|type54=line|from54=Interstate 84 (Oregon–Utah).map
|type55=line|from55=Interstate 84 (Pennsylvania–Massachusetts).map
|type56=line|from56=Interstate 85.map
|type57=line|from57=Interstate 86 (Idaho).map
|type58=line|from58=Interstate 86 (Pennsylvania–New York).map
|type59=line|from59=Interstate 87 (North Carolina) 1.map
|type60=line|from60=Interstate 87 (New York).map
|type61=line|from61=Interstate 88 (Illinois).map
|type62=line|from62=Interstate 88 (New York).map
|type63=line|from63=Interstate 89.map
|type64=line|from64=Interstate 90.map
|type65=line|from65=Interstate 91.map
|type66=line|from66=Interstate 93.map
|type67=line|from67=Interstate 94.map
|type68=line|from68=Interstate 95.map
|type69=line|from69=Interstate 96.map
|type70=line|from70=Interstate 97.map
|type71=line|from71=Interstate 99.map
|type72=line|from72=Interstate 35W (Texas).map
|type73=line|from73=Interstate 35W (Minnesota).map
}}
|map_custom= yes
|map_notes= Primary Interstate Highways in the 48 contiguous states. [[#Alaska, Hawaii, and Puerto Rico|Alaska, Hawaii, and Puerto Rico]] also have Interstate Highways.
|formed= {{start date and age|1956|06|29}}<ref name="FAHA56">{{cite magazine |last = Weingroff |first = Richard F. |title = Federal-Aid Highway Act of 1956, Creating the Interstate System |url = https://highways.dot.gov/public-roads/summer-1996/federal-aid-highway-act-1956-creating-interstate-system |magazine = Public Roads |volume = 60 |issue = 1 |date = Summer 1996 |access-date = March 16, 2012 |issn = 0033-3735 |archive-url = https://web.archive.org/web/20120307133751/http://www.fhwa.dot.gov/publications/publicroads/96summer/p96su10.cfm |archive-date = March 7, 2012 |url-status = live }}</ref>
|length_mi= 48890
|length_ref= {{#tag:ref|{{As of|2022}}.<ref name="hm20" />|group=lower-alpha}}
|interstate= Interstate X (I-X)
|links= BL
}}
<!--{{Highway system OSM map
|highway_system_qid= Q94247
|frame-width       = 350
|frame-height      = 200
|frame-align       = right
|text              = Interactive map of the Interstate Highway System
}}-->

{{Eisenhower series}}
The '''Dwight D. Eisenhower National System of Interstate and Defense Highways'''<!--that is the full, formal name; see the talk page or first citation-->, commonly known as the '''Interstate Highway System''', or the '''Eisenhower Interstate System''', is a network of [[controlled-access highway]]s that forms part of the [[National Highway System (United States)|National Highway System]] in the [[United States]]. The system extends throughout the [[contiguous United States]] and has routes in [[Hawaii]], [[Alaska]], and [[Puerto Rico]].

In the 20th century, the [[United States Congress]] began funding roadways through the [[Federal Aid Road Act of 1916]], and started an effort to construct a national road grid with the passage of the [[Federal Aid Highway Act of 1921]]. In 1926, the [[United States Numbered Highway System]] was established, creating the first national road numbering system for cross-country travel. The roads were funded and maintained by [[U.S. states]], and there were few national standards for road design. United States Numbered Highways ranged from two-lane country roads to multi-lane freeways. After [[Dwight D. Eisenhower]] became president in 1953, [[Presidency of Dwight D. Eisenhower|his administration]] developed a proposal for an interstate highway system, eventually resulting in the enactment of the [[Federal-Aid Highway Act of 1956]].

Unlike the earlier United States Numbered Highway System, the interstates were designed to be all freeways, with nationally unified standards for construction and signage. While some older freeways were adopted into the system, most of the routes were completely new. In dense urban areas, the choice of routing destroyed many well-established neighborhoods, often intentionally as part of a program of "[[urban renewal]]".<ref name=StrombergVox /> In the two decades following the 1956 Highway Act, the construction of the freeways displaced one million people,<ref name=GamboaNBC /> and as a result of the many [[Highway revolts in the United States|freeway revolts]] during this era, several planned Interstates were abandoned or re-routed to avoid urban cores.

Construction of the original Interstate Highway System was proclaimed complete in 1992, despite deviations from the original 1956 plan and several [[List of gaps in Interstate Highways|stretches that did not fully conform with federal standards]]. The construction of the Interstate Highway System cost approximately $114&nbsp;billion (equivalent to ${{formatprice|{{inflation|US-GDP|425000000000|2006}}}} in {{inflation-year|US-GDP}}). The system has continued to expand and grow as additional federal funding has provided for new routes to be added, and many [[List of future Interstate Highways|future Interstate Highways]] are currently either being planned or under construction.

Though heavily funded by the federal government, Interstate Highways are owned by the state in which they were built. With [[List of gaps in Interstate Highways|few exceptions]], all Interstates must meet [[Interstate Highway standards|specific standards]], such as having controlled access, physical barriers or [[median strip]]s between lanes of oncoming traffic, [[breakdown lane]]s, avoiding [[Intersection (road)|at-grade intersections]], no [[traffic light]]s, and complying with federal [[Road signs in the United States|traffic sign]] specifications. Interstate Highways use a numbering scheme in which primary Interstates are assigned one- or two-digit numbers, and shorter routes which branch off from longer ones are assigned three-digit numbers where the last two digits match the parent route. The Interstate Highway System is partially financed through the [[Highway Trust Fund]], which itself is funded by a combination of a federal [[Fuel taxes in the United States|fuel tax]] and transfers from the [[US Treasury|Treasury's]] general fund.<ref name=ShirleyCBO>{{cite report|last=Shirley|first=Chad|url=https://www.cbo.gov/publication/59634|title=Testimony on the Status of the Highway Trust Fund: 2023 Update|date=2023|institution=Congressional Budget Office|archive-date=March 30, 2024|access-date=March 30, 2024|archive-url=https://web.archive.org/web/20240330144952/https://www.cbo.gov/publication/59634|url-status=live}}</ref> Though federal legislation initially banned the collection of tolls, some Interstate routes are [[toll road]]s, either because they were [[grandfathered in]]to the system or because subsequent legislation has allowed for tolling of Interstates in some cases.

{{As of|2022}}, about one quarter of all vehicle miles driven in the country used the Interstate Highway System,<ref>{{cite book |type = Report |author = ((Office of Highway Policy Information)) |publisher = Federal Highway Administration |url = https://www.fhwa.dot.gov/policyinformation/statistics/2022/vm1.cfm |title = Table VM-1: Annual Vehicle Distance Traveled in Miles and Related Data, 2022, by Highway Category and Vehicle Type |date = February 5, 2024 |access-date = August 14, 2024 }}</ref> which has a total length of {{convert|48890|mi|km}}.<ref name="hm20">{{cite book |type = Report |author = ((Office of Highway Policy Information)) |publisher = Federal Highway Administration |url = https://www.fhwa.dot.gov/policyinformation/statistics/2022/hm20.cfm |title = Table HM-20: Public Road Length, 2022, Miles By Functional System |date = January 12, 2024 |access-date = August 14, 2024 }}</ref> In 2022 and 2023, the number of fatalities on the Interstate Highway System amounted to more than 5,000 people annually, with nearly 5,600 fatalities in 2022.<ref>{{cite report |author=National Center for Statistics and Analysis|date=May 2024|title=Early Estimates of Motor Vehicle Traffic Fatalities and Fatality Rate by Sub-Categories in 2023 |url=https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813581 |publisher=National Highway Traffic Safety Administration|docket=DOT HS 813 581 |access-date=August 14, 2024}}</ref>