# Interstate Highway System

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Network of freeways in the United States

"Interstate" redirects here. For the type of highway, see [Controlled-access highway](/source/Controlled-access_highway). For other uses, see [Interstate (disambiguation)](/source/Interstate_(disambiguation)).

Dwight D. Eisenhower National System of Interstate and Defense Highways Highway shields for Interstate 80, Business Loop Interstate 80, and the Eisenhower Interstate System Primary Interstate Highways in the 48 contiguous states. Alaska, Hawaii, and Puerto Rico also have Interstate Highways. System information Length 48,890 mi[a] (78,680 km) Formed June 29, 1956; 69 years ago (1956-06-29)[1] Highway names Interstates Interstate X (I-X) System links Interstate Highway System Main Auxiliary Suffixed Business Future

This article is part of a series about Dwight D. Eisenhower Early life Military career World War II Supreme Allied Commander in Europe D-Day Operation Overlord Surrender of Germany VE-Day Crusade in Europe 34th President of the United States Presidency Timeline Transition Inaugurations first second First Term Korean War Atoms for Peace Cold War New Look Domino theory Interstate Highway System Second Term Eisenhower Doctrine Sputnik crisis Missile gap NDEA NASA DARPA Civil Rights Act of 1957 Little Rock Nine Admission of states Alaska Hawaii U-2 incident Farewell Address Kennedy transition Presidential campaigns 1952 Primaries Draft movement VP candidate selection Convention Logistics TV broadcasts Election 1956 Primaries Convention Election Post-Presidency Legacy Presidential library and museum Tributes and memorials v t e

The **Dwight D. Eisenhower National System of Interstate and Defense Highways**, commonly known as the **Interstate Highway System**, or the **Eisenhower Interstate System**, is a network of [controlled-access highways](/source/Controlled-access_highway) that forms part of the [National Highway System](/source/National_Highway_System_(United_States)) in the [United States](/source/United_States). The system extends throughout the [contiguous United States](/source/Contiguous_United_States) and has routes in [Hawaii](/source/Hawaii), [Alaska](/source/Alaska), and [Puerto Rico](/source/Puerto_Rico).

In the 20th century, the [United States Congress](/source/United_States_Congress) began funding roadways through the [Federal Aid Road Act of 1916](/source/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](/source/Federal_Aid_Highway_Act_of_1921). In 1926, the [United States Numbered Highway System](/source/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](/source/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](/source/Dwight_D._Eisenhower) became president in 1953, [his administration](/source/Presidency_of_Dwight_D._Eisenhower) developed a proposal for an interstate highway system, eventually resulting in the enactment of the [Federal-Aid Highway Act of 1956](/source/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](/source/Urban_renewal)".[3] In the two decades following the 1956 Highway Act, the construction of the freeways displaced one million people,[4] and as a result of the many [freeway revolts](/source/Highway_revolts_in_the_United_States) 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 [stretches that did not fully conform with federal standards](/source/List_of_gaps_in_Interstate_Highways). The construction of the Interstate Highway System cost approximately $114 billion (equivalent to $634 billion in 2024). The system has continued to expand and grow as additional federal funding has provided for new routes to be added, and many [future Interstate Highways](/source/List_of_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 [few exceptions](/source/List_of_gaps_in_Interstate_Highways), all Interstates must meet [specific standards](/source/Interstate_Highway_standards), such as having controlled access, physical barriers or [median strips](/source/Median_strip) between lanes of oncoming traffic, [breakdown lanes](/source/Breakdown_lane), avoiding [at-grade intersections](/source/Intersection_(road)), no [traffic lights](/source/Traffic_light), and complying with federal [traffic sign](/source/Road_signs_in_the_United_States) 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](/source/Highway_Trust_Fund), which itself is funded by a combination of a federal [fuel tax](/source/Fuel_taxes_in_the_United_States) and transfers from the [Treasury's](/source/US_Treasury) general fund.[5] Though federal legislation initially banned the collection of tolls, some Interstate routes are [toll roads](/source/Toll_road), either because they were [grandfathered into](/source/Grandfathered_in) the system or because subsequent legislation has allowed for tolling of Interstates in some cases.

As of 2022[\[update\]](https://en.wikipedia.org/w/index.php?title=Interstate_Highway_System&action=edit), about one quarter of all vehicle miles driven in the country used the Interstate Highway System,[6] which has a total length of 48,890 miles (78,680 km).[2] 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.[7] Neighborhoods closest to Interstate Highways have elevated rates of asthma and cancer.[8]

## History

### Planning

[Remarks in Cadillac Square, Detroit](https://en.wikipedia.org/wiki/File:Cadillacsquareexcerpt.ogg)

President Eisenhower delivered remarks about the need for a new highway program at [Cadillac Square](/source/Cadillac_Square) in Detroit on October 29, 1954
[Text of speech excerpt](https://www.fhwa.dot.gov/interstate/audiotext.cfm#cadillac)

*Problems playing this file? See [media help](https://en.wikipedia.org/wiki/Help:Media).*

The Pershing Map

FDR's hand-drawn map from 1938

The United States government's efforts to construct a national network of highways began on an *ad hoc* basis with the passage of the [Federal Aid Road Act of 1916](/source/Federal_Aid_Road_Act_of_1916), which provided $75 million over a five-year period for [matching funds](/source/Matching_funds) to the states for the construction and improvement of highways.[9] The nation's revenue needs associated with [World War I](/source/World_War_I) prevented any significant implementation of this policy, which expired in 1921.

In December 1918, E. J. Mehren, a civil engineer and the editor of *[Engineering News-Record](/source/Engineering_News-Record)*, presented his "A Suggested National Highway Policy and Plan"[10] during a gathering of the State Highway Officials and Highway Industries Association at the Congress Hotel in Chicago.[11] In the plan, Mehren proposed a 50,000-mile (80,000 km) system, consisting of five east–west routes and 10 north–south routes. The system would include two percent of all roads and would pass through every state at a cost of $25,000 per mile ($16,000/km), providing commercial as well as military transport benefits.[10]

In 1919, the US Army sent an expedition across the US to determine the difficulties that military vehicles would have on a cross-country trip. Leaving from [the Ellipse](/source/The_Ellipse) near the [White House](/source/White_House) on July 7, the [Motor Transport Corps convoy](/source/1919_Motor_Transport_Corps_convoy) needed 62 days to drive 3,200 miles (5,100 km) on the [Lincoln Highway](/source/Lincoln_Highway) to the [Presidio of San Francisco](/source/Presidio_of_San_Francisco) along the [Golden Gate](/source/Golden_Gate). The convoy suffered many setbacks and problems on the route, such as poor-quality bridges, broken crankshafts, and engines clogged with desert sand.[12]

[Dwight Eisenhower](/source/Dwight_D._Eisenhower), then a 28-year-old [brevet](/source/Brevet_(military)) lieutenant colonel,[13] accompanied the trip "through darkest America with truck and tank," as he later described it. Some roads in the West were a "succession of dust, ruts, pits, and holes."[12]

As the landmark 1916 law expired, new legislation was passed—the [Federal Aid Highway Act of 1921](/source/Federal_Aid_Highway_Act_of_1921) (Phipps Act). This new road construction initiative once again provided for federal matching funds for road construction and improvement, $75 million allocated annually.[14] Moreover, this new legislation for the first time sought to target these funds to the construction of a national road grid of interconnected "primary highways", setting up cooperation among the various state highway planning boards.[14]

The [Bureau of Public Roads](/source/Federal_Highway_Administration) asked the [Army](/source/United_States_Army) to provide a list of roads that it considered necessary for national defense.[15] In 1922, General [John J. Pershing](/source/John_J._Pershing), former head of the [American Expeditionary Force](/source/American_Expeditionary_Force) in Europe during the war, complied by submitting a detailed network of 20,000 miles (32,000 km) of interconnected primary highways—the so-called [Pershing Map](/source/Pershing_Map).[16]

A boom in road construction followed throughout the decade of the 1920s, with such projects as the [New York parkway system](/source/Parkways_in_New_York_State) constructed as part of a new national highway system. As automobile traffic increased, planners saw a need for such an interconnected national system to supplement the existing, largely non-freeway, [United States Numbered Highways](/source/United_States_Numbered_Highways) system. By the late 1930s, planning had expanded to a system of new superhighways.

[Wikisource](/source/Wikisource) has original text related to this section:

***[Toll Roads and Free Roads](https://en.wikisource.org/wiki/Toll_Roads_and_Free_Roads)***

***[Interregional Highways](https://en.wikisource.org/wiki/Interregional_Highways)***

In 1938, President [Franklin D. Roosevelt](/source/Franklin_D._Roosevelt) gave [Thomas MacDonald](/source/Thomas_Harris_MacDonald), chief at the Bureau of Public Roads, a hand-drawn map of the United States marked with eight superhighway corridors for study.[17] In 1939, Bureau of Public Roads Division of Information chief [Herbert S. Fairbank](/source/Herbert_S._Fairbank) wrote a report called *Toll Roads and Free Roads*, "the first formal description of what became the Interstate Highway System" and, in 1944, the similarly themed *Interregional Highways*.[18]

1947 Interstate Highway map

In 1947, working with recommendations from State Highway departments and the Department of Defense, the Federal Highway Commission and the Federal Works Administration announced the selection of 37,700 miles of routes. The 1947 map would serve as the basis for the 1956 map.[19]

### Federal Aid Highway Act of 1956

Main article: [Federal Aid Highway Act of 1956](/source/Federal_Aid_Highway_Act_of_1956)

The Interstate Highway System gained a champion in President Dwight D. Eisenhower, who was influenced by his experiences as a young Army officer crossing the country in the 1919 Motor Transport Corps convoy that drove in part on the [Lincoln Highway](/source/Lincoln_Highway), the first road across America. He recalled that, "The old convoy had started me thinking about good two-lane highways... the wisdom of broader ribbons across our land."[12] Eisenhower also gained an appreciation of the [Reichsautobahn](/source/Reichsautobahn) system, the first "national" implementation of modern Germany's [Autobahn](/source/German_autobahns) network, as a necessary component of a national defense system while he was serving as [Supreme Commander](/source/Supreme_Commander_of_the_Allied_Expeditionary_Force) of [Allied Forces](/source/Allies_of_World_War_II) in Europe during [World War II](/source/European_Theatre_of_World_War_II).[20] In 1954, Eisenhower appointed General [Lucius D. Clay](/source/Lucius_D._Clay) to head a committee charged with proposing an interstate highway system plan.[21] Summing up motivations for the construction of such a system, Clay stated,

It was evident we needed better highways. We needed them for safety, to accommodate more automobiles. We needed them for defense purposes, if that should ever be necessary. And we needed them for the economy. Not just as a public works measure, but for future growth.[22]

[Wikisource](/source/Wikisource) has original text related to this section:

***[National Highway Program](https://en.wikisource.org/wiki/National_Highway_Program)***

***[A 10-Year National Highway Program](https://en.wikisource.org/wiki/A_10-Year_National_Highway_Program)***

***[General Location of National System of Interstate Highways](https://en.wikisource.org/wiki/General_Location_of_National_System_of_Interstate_Highways)***

Clay's committee proposed a 10-year, $100 billion program ($1.2 trillion in 2025), which would build 40,000 miles (64,000 km) of [divided highways](/source/Dual_carriageway) linking all American cities with a population of greater than 50,000. Eisenhower initially preferred a system consisting of [toll roads](/source/Toll_road), but Clay convinced Eisenhower that toll roads were not feasible outside the highly populated coastal regions. In February 1955, Eisenhower forwarded Clay's proposal to Congress. The bill quickly won approval in the Senate, but House Democrats objected to the use of public [bonds](/source/Bond_(finance)) as the means to finance construction. Eisenhower and the House Democrats agreed to instead finance the system through the [Highway Trust Fund](/source/Highway_Trust_Fund), which itself would be funded by a [gasoline](/source/Gasoline) tax.[23] In June 1956, Eisenhower signed the [Federal Aid Highway Act of 1956](/source/Federal_Aid_Highway_Act_of_1956) into law. Under the act, the federal government would pay for 90 percent of the cost of construction of Interstate Highways. Each Interstate Highway was required to be a [freeway](/source/Freeway) with at least four lanes and no at-grade crossings.[24]

The publication in 1955 of the *General Location of National System of Interstate Highways*, informally known as the *Yellow Book*, mapped out what became the Interstate Highway System.[25] Assisting in the planning was [Charles Erwin Wilson](/source/Charles_Erwin_Wilson), who was still head of [General Motors](/source/General_Motors) when President Eisenhower selected him as Secretary of Defense in January 1953.

### Construction

1955 map: The planned status of US Highways in 1965, as a result of the developing Interstate Highway System

[I‑55](/source/Interstate_55_in_Mississippi) under construction in [Mississippi](/source/Mississippi) in May 1972

1957 aerial photograph showing a recently constructed interchange on I-5 in [Glendale, California](/source/Glendale%2C_California)

Some sections of highways that became part of the Interstate Highway System actually began construction earlier.

Three states have claimed the title of first Interstate Highway. Missouri claims that the first three contracts under the new program were signed in Missouri on August 2, 1956. The first contract signed was for upgrading a section of [US Route 66](/source/U.S._Route_66) to what is now designated [Interstate 44](/source/Interstate_44).[26] On August 13, 1956, work began on [US 40](/source/US_Route_40) (now I-70) in St. Charles County.[27][26]

Kansas claims that it was the first to start paving after the act was signed. Preliminary construction had taken place before the act was signed, and paving started September 26, 1956. The state marked its portion of [I-70](/source/Interstate_70) as the first project in the United States completed under the provisions of the new Federal-Aid Highway Act of 1956.[26]

The [Pennsylvania Turnpike](/source/Pennsylvania_Turnpike) could also be considered one of the first Interstate Highways, and is nicknamed "Grandfather of the Interstate System".[27] On October 1, 1940, 162 miles (261 km) of the highway now designated I‑70 and I‑76 opened between [Irwin](/source/Irwin%2C_Pennsylvania) and [Carlisle](/source/Carlisle%2C_Pennsylvania). The [Commonwealth of Pennsylvania](/source/Pennsylvania) refers to the turnpike as the Granddaddy of the Pikes, a reference to [turnpikes](/source/Toll_road).[26]

Milestones in the construction of the Interstate Highway System include:

- October 17, 1974: [Nebraska](/source/Nebraska) becomes the first state to complete all of its mainline Interstate Highways with the dedication of its final piece of [I-80](/source/Interstate_80_in_Nebraska).[28]

- October 12, 1979: The final section of the Canada to Mexico freeway [Interstate 5](/source/Interstate_5) is dedicated near [Stockton, California](/source/Stockton%2C_California). Representatives of the two neighboring nations attended the dedication to commemorate the first continuous freeway connecting the North American countries.[29]

- August 22, 1986: The final section of the coast-to-coast [I-80](/source/Interstate_80) ([San Francisco, California](/source/San_Francisco%2C_California), to [Teaneck, New Jersey](/source/Teaneck%2C_New_Jersey)) is dedicated on the western edge of [Salt Lake City, Utah](/source/Salt_Lake_City%2C_Utah), making I-80 the world's first continuous freeway to span from the Atlantic to Pacific Ocean and, at the time, the longest continuous freeway in the world. The section spanned from [Redwood Road](/source/Utah_State_Route_68) to just west of the [Salt Lake City International Airport](/source/Salt_Lake_City_International_Airport). At the dedication it was noted that coincidentally this was only 50 miles (80 km) from [Promontory Summit](/source/Promontory_Summit), where a similar feat was accomplished nearly 120 years prior, the driving of the [golden spike](/source/Golden_spike) of the United States' [First transcontinental railroad](/source/First_transcontinental_railroad).[30][31][32]

- August 10, 1990: The final section of coast-to-coast [I-10](/source/Interstate_10) ([Santa Monica, California](/source/Santa_Monica%2C_California), to [Jacksonville, Florida](/source/Jacksonville%2C_Florida)) is dedicated, the [Papago Freeway Tunnel](/source/Papago_Freeway_Tunnel) under downtown [Phoenix, Arizona](/source/Phoenix%2C_Arizona). Completion of this section was delayed due to a [freeway revolt](/source/Highway_revolt) that forced the cancellation of an originally planned elevated routing.[33]

- September 12, 1991: [I-90](/source/Interstate_90) becomes the final coast-to-coast Interstate Highway ([Seattle, Washington](/source/Seattle%2C_Washington) to [Boston, Massachusetts](/source/Boston%2C_Massachusetts)) to be completed with the dedication of an elevated [viaduct](/source/Viaduct) bypassing [Wallace, Idaho](/source/Wallace%2C_Idaho), which opened a week earlier.[34][35] This section was delayed after residents forced the cancellation of the originally planned at-grade alignment that would have demolished much of [downtown Wallace](/source/Wallace_Historic_District). The residents accomplished this feat by arranging for most of the downtown area to be declared a [historic district](/source/Historic_districts_in_the_United_States) and listed on the [National Register of Historic Places](/source/National_Register_of_Historic_Places); this succeeded in blocking the path of the original alignment. Two days after the dedication residents held a mock funeral celebrating the removal of the last stoplight on a transcontinental Interstate Highway.[33][36]

- October 14, 1992: The original Interstate Highway System is proclaimed to be complete with the opening of [I-70](/source/Interstate_70_in_Colorado) through [Glenwood Canyon](/source/Glenwood_Canyon) in [Colorado](/source/Colorado). This section is considered an engineering marvel with a 12-mile (19 km) span featuring 40 bridges and numerous tunnels and is one of the most expensive rural highways per mile built in the United States.[37][38]

The initial cost estimate for the system was $25 billion over 12 years; it ended up costing $114 billion (equivalent to $425 billion in 2006[39] or $634 billion in 2024[40]) and took 35 years.[41]

### 1992–present

#### Discontinuities

Main article: [List of gaps in Interstate Highways](/source/List_of_gaps_in_Interstate_Highways)

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](/source/General_of_the_Army_(United_States)) during World War II.

The system was proclaimed complete in 1992, but two of the original Interstates—[I-95](/source/Interstate_95) and [I-70](/source/Interstate_70)—were not continuous: both of these discontinuities were due to local opposition, which blocked efforts to build the necessary connections to fully complete the system. I-95 was made a continuous freeway in 2018,[42] and thus I-70 remains the only original Interstate with a discontinuity.

I-95 was discontinuous in New Jersey because of the cancellation of the [Somerset Freeway](/source/Somerset_Freeway). This situation was remedied when the construction of the [Pennsylvania Turnpike/Interstate 95 Interchange Project](/source/Pennsylvania_Turnpike%2FInterstate_95_Interchange_Project) started in 2010[43] and partially opened on September 22, 2018, which was already enough to fill the gap.[42]

However, I-70 remains discontinuous in [Pennsylvania](/source/Pennsylvania), because of the lack of a direct interchange with the [Pennsylvania Turnpike](/source/Pennsylvania_Turnpike) at the eastern end of the [concurrency](/source/Concurrency_(road)) near [Breezewood](/source/Breezewood%2C_Pennsylvania). Traveling in either direction, I-70 traffic must exit the freeway and use a short stretch of [US 30](/source/U.S._Route_30_in_Pennsylvania) (which includes a number of roadside services) to rejoin I-70. The interchange was not originally built because of a legacy federal funding rule, since relaxed, which restricted the use of federal funds to improve roads financed with tolls.[44] Solutions have been proposed to eliminate the discontinuity, but they have been blocked by local opposition, fearing a loss of business.[45]

#### Expansions and removals

See also: [Future Interstate Highways](/source/Future_Interstate_Highways) and [Freeway removal](/source/Freeway_removal)

The Interstate Highway System has been expanded numerous times. The expansions have both created new designations and extended existing designations. For example, [I-49](/source/Interstate_49), added to the system in the 1980s as a freeway in [Louisiana](/source/Louisiana), was designated as an expansion corridor, and FHWA approved the expanded route north from [Lafayette, Louisiana](/source/Lafayette%2C_Louisiana), to [Kansas City, Missouri](/source/Kansas_City%2C_Missouri). The freeway exists today as separate completed segments, with segments under construction or in the planning phase between them.[46]

In 1966, the FHWA designated the entire Interstate Highway System as part of the larger [Pan-American Highway](/source/Pan-American_Highway) System,[47] and at least two proposed Interstate expansions were initiated to help trade with Canada and Mexico spurred by the [North American Free Trade Agreement](/source/North_American_Free_Trade_Agreement) (NAFTA). Long-term plans for [I-69](/source/Interstate_69), which currently exists in several separate completed segments (the largest of which are in [Indiana](/source/Indiana) and [Texas](/source/Texas)), is to have the highway route extend from [Tamaulipas](/source/Tamaulipas), Mexico to [Ontario](/source/Ontario), Canada. The planned [I-11](/source/Interstate_11) will then bridge the Interstate gap between [Phoenix, Arizona](/source/Phoenix%2C_Arizona) and [Las Vegas, Nevada](/source/Las_Vegas%2C_Nevada), and thus form part of the [CANAMEX Corridor](/source/CANAMEX_Corridor) (along with [I-19](/source/Interstate_19), and portions of [I-10](/source/Interstate_10) and [I-15](/source/Interstate_15)) between [Sonora](/source/Sonora), Mexico and [Alberta](/source/Alberta), Canada.

### Opposition, cancellations, and removals

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Main article: [Highway revolts in the United States](/source/Highway_revolts_in_the_United_States)

The fervor of [urban renewal](/source/Urban_renewal) led to the routing of [Interstate 81](/source/Interstate_81_in_New_York) through the middle of [Syracuse's 15th ward](/source/15th_Ward_(Syracuse%2C_New_York)) in the 1960s. The viaduct is now slated for demolition.[48]

Political opposition from residents canceled many freeway projects around the United States, including:

- [I-40](/source/Interstate_40_in_Tennessee) in Memphis, Tennessee was rerouted and part of the original I-40 is still in use as the eastern half of [Sam Cooper Boulevard](/source/Sam_Cooper_Boulevard).[49]

- Extensions of [I-66](/source/Interstate_66) in the [District of Columbia](/source/District_of_Columbia), including an auxiliary route I-266, were abandoned in 1977.[50]

- [I-69](/source/Interstate_69) was to continue past its terminus at Interstate 465 to intersect with [Interstate 70](/source/Interstate_70) and [Interstate 65](/source/Interstate_65) at the north split, northeast of downtown [Indianapolis](/source/Indianapolis). Though local opposition led to the cancellation of this project in 1981, bridges and ramps for the connection into the "north split" remained until it was rebuilt in 2023.

- [I-70](/source/Interstate_70_in_Maryland) in [Baltimore](/source/Baltimore) was supposed to run from the Baltimore Beltway ([Interstate 695](/source/Interstate_695_in_Maryland)), which surrounds the city to terminate at [I-95](/source/I-95), the East Coast thoroughfare that runs through Maryland and Baltimore on a diagonal course, northeast to southwest; the connection was cancelled on the mid-1970s due to its routing through [Gwynns Falls-Leakin Park](/source/Gwynns_Falls_Leakin_Park), a wilderness urban park reserve following the [Gwynns Falls](/source/Gwynns_Falls) stream through West Baltimore. This included the cancellation of [I-170](/source/Interstate_170_(Maryland)), partially built and in use as US 40, and nicknamed the Highway to Nowhere. The freeway stub of I-70 inside the Beltway was renumbered MD 570 in 2014, but continues to bear I-70 signs.

- [I-78](/source/Interstate_78_in_New_York) in New York City was canceled along with portions of [I-278](/source/Interstate_278), [I-478](/source/Interstate_478), and [I-878](/source/Interstate_878). I-878 was supposed to be part of I-78, and I-478 and I-278 were to be spur routes.

- [I-80](/source/Interstate_80_in_California) in San Francisco was originally planned to travel past the city's Civic Center along the Panhandle Freeway into [Golden Gate Park](/source/Golden_Gate_Park) and terminate at the original alignment of [I-280](/source/Interstate_280_(California))/[SR 1](/source/California_State_Route_1). The city canceled this and several other freeways in 1958. Similarly, more than 20 years later, Sacramento canceled plans to upgrade I-80 to Interstate Standards and rerouted the freeway on what was then I-880 that traveled north of Downtown Sacramento.

- [I-83](/source/Interstate_83), southern extension of the [Jones Falls Expressway](/source/Jones_Falls_Expressway) (southern [I-83](/source/I-83)) in [Baltimore](/source/Baltimore) was supposed to run along the waterfront of the [Patapsco River](/source/Patapsco_River) / [Baltimore Harbor](/source/Helen_Delich_Bentley_Port_of_Baltimore) to connect to [I-95](/source/Interstate_95_in_Maryland), bisecting the historic neighborhoods of [Fells Point](/source/Fells_Point%2C_Baltimore) and [Canton](/source/Canton%2C_Baltimore), but the connection was never built.

- [I-84](/source/Interstate_84_(Pennsylvania-Massachusetts)) in [Connecticut](/source/Connecticut) was once planned to fork east of Hartford, into an [I-86](/source/Interstate_84_(Pennsylvania%E2%80%93Massachusetts)) to Sturbridge, Massachusetts, and I-84 to Providence, R.I. The plan was cancelled, primarily because of anticipated impact on a major Rhode Island reservoir. The I-84 designation was restored to the highway to Sturbridge, and other numbering was used for completed Eastern sections of what had been planned as part of I-84.

- [I-95](/source/Interstate_95_in_Maryland) through the [District of Columbia](/source/District_of_Columbia) into [Maryland](/source/Maryland) was abandoned in 1977. Instead it was rerouted to [I-495 (Capital Beltway)](/source/Interstate_495_(Capital_Beltway)). The completed section is now [I-395](/source/Interstate_395_(Virginia%E2%80%93District_of_Columbia)).

- [I-95](/source/Interstate_95_in_Massachusetts) was originally planned to run up the [Southwest Expressway](/source/Southwest_Corridor_(Massachusetts)) and meet [I-93](/source/Interstate_93), where the two highways would travel along the [Central Artery](/source/Central_Artery) through downtown [Boston](/source/Boston), but was rerouted onto the [Route 128](/source/Massachusetts_State_Highway_128) beltway due to widespread opposition. This revolt also included the cancellation of the [Inner Belt](/source/Interstate_695_(Massachusetts)), connecting I-93 to [I-90](/source/Massachusetts_Turnpike) and a cancelled section of the [Northwest Expressway](/source/U.S._Route_3) which would have carried [US 3](/source/U.S._Route_3) inside the Route 128 beltway, meeting with [Route 2](/source/Massachusetts_Route_2) in [Cambridge](/source/Cambridge%2C_Massachusetts).

In addition to cancellations, removals of freeways are:

- [I-81](/source/Interstate_81_in_New_York) in [Syracuse, New York](/source/Syracuse%2C_New_York), which bisects the city's 15th Ward neighborhood, is planned to be torn down and replaced with a [boulevard](/source/Boulevard) that accommodates pedestrians.[48][51] Freeway traffic would be rerouted along [I-481](/source/I-481).[51]

## Standards

Main article: [Interstate Highway standards](/source/Interstate_Highway_standards)

The [American Association of State Highway and Transportation Officials](/source/American_Association_of_State_Highway_and_Transportation_Officials) (AASHTO) has defined a set of standards that all new Interstates must meet unless a waiver from the [Federal Highway Administration](/source/Federal_Highway_Administration) (FHWA) is obtained. One almost absolute standard is the [controlled access](/source/Controlled-access_highway) nature of the roads. With few [exceptions](/source/List_of_gaps_in_Interstate_Highways), [traffic lights](/source/Traffic_light) (and cross traffic in general) are limited to [toll booths](/source/Toll_house) and [ramp meters](/source/Ramp_meter) (metered flow control for lane merging during [rush hour](/source/Rush_hour)).

### Speed limits

Further information: [Speed limits in the United States](/source/Speed_limits_in_the_United_States) and [National Maximum Speed Law](/source/National_Maximum_Speed_Law)

[I-95](/source/Interstate_95_in_Maryland) in [Columbia, Maryland](/source/Columbia%2C_Maryland), built to modern standards.

A rural stretch of [I-5](/source/Interstate_5_in_California) in California; two lanes in each direction are separated by a large grassy [median](/source/Central_reservation) and cross-traffic is limited to [grade separations](/source/Grade_separation) such as this overpass.

Being [freeways](/source/Freeway), Interstate Highways usually have the highest [speed limits](/source/Speed_limit) in a given area. Speed limits are determined by individual states. From 1975 to 1986, the maximum speed limit on any highway in the United States was 55 miles per hour (90 km/h), in accordance with federal law.[52]

Typically, lower limits are established in [Northeastern](/source/Northeastern_United_States) and coastal states, while higher speed limits are established in inland states west of the [Mississippi River](/source/Mississippi_River).[53] For example, the maximum speed limit is 75 mph (120 km/h) in northern Maine, varies between 50 and 70 mph (80 and 115 km/h)[54] from southern Maine to New Jersey, and is 50 mph (80 km/h) in New York City and the District of Columbia.[53]

### Other uses

As one of the components of the [National Highway System](/source/National_Highway_System_(United_States)), 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](/source/Strategic_Highway_Network), a system of roads identified as critical to the [US Department of Defense](/source/US_Department_of_Defense).[55]

The system has also been used to facilitate evacuations in the face of hurricanes and other natural disasters. An option for maximizing traffic throughput on a highway is to reverse the flow of traffic on one side of a divider so that all lanes become outbound lanes. This procedure, known as [contraflow lane reversal](/source/Contraflow_lane_reversal), has been employed several times for hurricane evacuations. After public outcry regarding the inefficiency of evacuating from southern Louisiana prior to [Hurricane Georges](/source/Hurricane_Georges)' landfall in September 1998, government officials looked towards contraflow to improve evacuation times. In [Savannah, Georgia](/source/Savannah%2C_Georgia), and [Charleston, South Carolina](/source/Charleston%2C_South_Carolina), in 1999, lanes of [I-16](/source/Interstate_16_in_Georgia) and [I-26](/source/Interstate_26_in_South_Carolina) were used in a contraflow configuration in anticipation of [Hurricane Floyd](/source/Hurricane_Floyd) with mixed results.[56]

In 2004, contraflow was employed ahead of [Hurricane Charley](/source/Hurricane_Charley) in the [Tampa, Florida](/source/Tampa%2C_Florida) area and on the [Gulf Coast](/source/Gulf_Coast_of_the_United_States) before the landfall of [Hurricane Ivan](/source/Hurricane_Ivan);[57] however, evacuation times there were no better than previous evacuation operations. Engineers began to apply lessons learned from the analysis of prior contraflow operations, including limiting exits, removing troopers (to keep traffic flowing instead of having drivers stop for directions), and improving the dissemination of public information. As a result, the 2005 evacuation of New Orleans, Louisiana, prior to [Hurricane Katrina](/source/Hurricane_Katrina) ran much more smoothly.[58]

According to [urban legend](/source/Urban_legend), early regulations required 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. There is no evidence of this rule being included in any Interstate legislation.[59][60] It is also [commonly believed](/source/List_of_common_misconceptions) the Interstate Highway System was built for the sole purpose of evacuating cities in the event of [nuclear warfare](/source/Nuclear_warfare). While military motivations were present, the primary motivations were civilian.[61][62]

## Numbering system

### Primary (one- and two-digit) Interstates

See also: [List of primary Interstate Highways](/source/List_of_primary_Interstate_Highways) and [List of auxiliary Interstate Highways](/source/List_of_auxiliary_Interstate_Highways)

Odd numbers run north–south with numbers increasing from west to east, while even numbers run east–west with numbers increasing from south to north.

[I‑78](/source/Interstate_78_in_Pennsylvania) and [US 22](/source/U.S._Route_22_in_Pennsylvania) in [Berks County, Pennsylvania](/source/Berks_County%2C_Pennsylvania) (2008)

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.[63] Within the contiguous United States, primary Interstates—also called main line Interstates or two-digit Interstates—are assigned numbers less than 100.[63]

While numerous exceptions do exist, there is a general scheme for numbering Interstates. Primary Interstates are assigned one- or two-digit numbers, while shorter routes (such as spurs, loops, and short connecting roads) are assigned three-digit numbers where the last two digits match the parent route (thus, [I-294](/source/Interstate_294) is a loop that connects at both ends to [I-94](/source/Interstate_94), while [I-787](/source/Interstate_787) is a short spur route attached to [I-87](/source/Interstate_87_(New_York))). In the numbering scheme for the primary routes, east–west highways are assigned even numbers and north–south highways are assigned odd numbers. Odd route numbers increase from west to east, and even-numbered routes increase from south to north (to avoid confusion with the [US Highways](/source/United_States_Numbered_Highway_System), which increase from east to west and north to south).[64] This numbering system usually holds true even if the local direction of the route does not match the compass directions. Numbers [divisible](/source/Division_(mathematics)) by five are intended to be major arteries among the primary routes, carrying traffic long distances.[65][66] Primary north–south Interstates increase in number from [I-5](/source/Interstate_5) between Canada and Mexico along the [West Coast](/source/West_Coast_of_the_United_States) to [I‑95](/source/Interstate_95) between Canada and [Miami, Florida](/source/Miami%2C_Florida) along the [East Coast](/source/East_Coast_of_the_United_States). Major west–east arterial Interstates increase in number from [I-10](/source/Interstate_10) between [Santa Monica, California](/source/Santa_Monica%2C_California), and [Jacksonville, Florida](/source/Jacksonville%2C_Florida), to [I-90](/source/Interstate_90) between [Seattle, Washington](/source/Seattle%2C_Washington), and [Boston, Massachusetts](/source/Boston%2C_Massachusetts), with two exceptions. There are no I-50 and I-60, as routes with those numbers would likely pass through states that currently have US Highways with the same numbers, which is generally disallowed under highway administration guidelines.[63][67]

Several two-digit numbers are shared between unconnected road segments at opposite ends of the country for various reasons. Some such highways are incomplete Interstates (such as [I-69](/source/Interstate_69) and [I-74](/source/Interstate_74)) and some just happen to share route designations (such as [I-76](/source/Interstate_76_(disambiguation)), [I-84](/source/Interstate_84_(disambiguation)), [I‑86](/source/Interstate_86_(disambiguation)), [I-87](/source/Interstate_87_(disambiguation)), and [I-88](/source/Interstate_88_(disambiguation))). Some of these were due to a change in the numbering system as a result of a new policy adopted in 1973. Previously, letter-suffixed numbers were used for long spurs off primary routes; for example, western [I‑84](/source/Interstate_84_(west)) was I‑80N, as it went north from [I‑80](/source/Interstate_80). The new policy stated, "No new divided numbers (such as [I-35W](/source/Interstate_35W_(disambiguation)) and [I-35E](/source/Interstate_35E_(disambiguation)), etc.) shall be adopted." The new policy also recommended that existing divided numbers be eliminated as quickly as possible; however, an [I-35W](/source/Interstate_35W_(Texas)) and [I-35E](/source/Interstate_35E_(Texas)) (East and West) still exist in the [Dallas–Fort Worth metroplex](/source/Dallas%E2%80%93Fort_Worth_metroplex) in Texas, and an [I-35W](/source/Interstate_35W_(Minnesota)) and [I-35E](/source/Interstate_35E_(Minnesota)) that run through [Minneapolis](/source/Minneapolis) and [Saint Paul](/source/Saint_Paul%2C_Minnesota), Minnesota, still exist.[63] Additionally, due to Congressional requirements, three sections of I-69 in southern Texas will be divided into [I-69W](/source/Interstate_69W), [I-69E](/source/Interstate_69E), and [I-69C](/source/Interstate_69C) (for Central).[68]

AASHTO policy allows dual numbering to provide continuity between major control points.[63] This is referred to as a [concurrency](/source/Concurrency_(road)) or overlap. For example, [I‑75](/source/Interstate_75_in_Georgia) and [I‑85](/source/Interstate_85_in_Georgia) share the same roadway in [Atlanta](/source/Atlanta); this 7.4-mile (11.9 km) section, called the [Downtown Connector](/source/Downtown_Connector), is labeled both I‑75 and I‑85. Concurrencies between Interstate and US Highway numbers are also allowed in accordance with AASHTO policy, as long as the length of the concurrency is reasonable.[63] In rare instances, two highway designations sharing the same roadway are signed as traveling in opposite directions; one such [wrong-way concurrency](/source/Wrong-way_concurrency) is found between [Wytheville](/source/Wytheville%2C_Virginia) and [Fort Chiswell](/source/Fort_Chiswell%2C_Virginia), Virginia, where [I‑81](/source/Interstate_81_in_Virginia) north and [I‑77](/source/Interstate_77_in_Virginia) south are equivalent (with that section of road traveling almost due east), as are I‑81 south and I‑77 north.

### Auxiliary (three-digit) Interstates

See also: [List of auxiliary Interstate Highways](/source/List_of_auxiliary_Interstate_Highways)

Examples of the auxiliary Interstate Highway numbering system. An odd hundreds digit means the route connects at only one end to the rest of the interstate system, known as a "spur route" (see I-310 and I-510 in image). An even hundreds digit means the route connects at both ends, which could be a bypass route (which has two termini) (see I-210 and I-810 in image) or a radial route (known also as a beltway, beltline, or circumferential route) (see I-610 in image).

Auxiliary Interstate Highways are circumferential, radial, or spur highways that principally serve [urban areas](/source/Urban_area). These types of Interstate Highways are given three-digit route numbers, which consist of a single digit prefixed to the two-digit number of its parent Interstate Highway. Spur routes deviate from their parent and do not return; these are given an odd first digit. Circumferential and radial loop routes return to the parent, and are given an even first digit. Unlike primary Interstates, three-digit Interstates are signed as either east–west or north–south, depending on the general orientation of the route, without regard to the route number. For instance, [I-190](/source/Interstate_190_(Massachusetts)) in Massachusetts is labeled north–south, while [I-195](/source/Interstate_195_(New_Jersey)) in New Jersey is labeled east–west. Some looped Interstate routes use [inner–outer directions](/source/Inner%E2%80%93outer_directions) instead of compass directions, when the use of compass directions would create ambiguity. Due to the large number of these routes, auxiliary route numbers may be repeated in different states along the mainline.[69] Some auxiliary highways do not follow these guidelines, however.

### Alaska, Hawaii, and Puerto Rico

Map of routes in [Puerto Rico](/source/Puerto_Rico) that receive funding from the Interstate program, but are not signed as Interstate Highways

Map of routes in Alaska that receive funding from the Interstate program, but are not signed as Interstate Highways

The Interstate Highway System also extends to [Alaska](/source/Alaska), [Hawaii](/source/Hawaii), and [Puerto Rico](/source/Puerto_Rico), even though they have no direct land connections to any other states or territories. However, their residents still pay federal fuel and tire taxes.

The Interstates in Hawaii, all located on the most populous island of [Oahu](/source/Oahu), carry the prefix **H**. There are three one-digit routes in the state ([H-1](/source/Interstate_H-1), [H-2](/source/Interstate_H-2), and [H-3](/source/Interstate_H-3)) and one auxiliary route ([H-201](/source/Interstate_H-201)). These Interstates connect several [military](/source/United_States_Air_Force) and [naval](/source/United_States_Navy) bases together, as well as the important communities spread across Oahu, and especially within the urban core of [Honolulu](/source/Honolulu).

Both Alaska and Puerto Rico also have public highways that receive 90 percent of their funding from the Interstate Highway program. The [Interstates of Alaska](/source/Interstate_Highways_in_Alaska) and [Puerto Rico](/source/Interstate_Highways_in_Puerto_Rico) are numbered sequentially in order of funding without regard to the rules on odd and even numbers. They also carry the prefixes **A** and **PR**, respectively. However, these highways are signed according to their local designations, not their Interstate Highway numbers. Furthermore, these routes were neither planned according to nor constructed to the official [Interstate Highway standards](/source/Interstate_Highway_standards).[70]

### Mile markers and exit numbers

Most Interstate Highways use distance-based [exit numbers](/source/Exit_numbers_in_the_United_States) so that the exit number is the same as the nearest mile marker. The southernmost or westernmost terminus within the state is the beginning point for interchange exit numbering.[71] If multiple exits occur within the same mile, letter suffixes may be appended to the numbers in alphabetical order starting with A.[72] A small number of Interstate Highways (mostly in the Northeastern United States) use sequential-based exit numbering schemes (where each exit is numbered in order starting with 1, without regard for the mile markers on the road). One Interstate Highway, [I-19](/source/Interstate_19) in Arizona, is signed with kilometer-based exit numbers.[*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed)*] In the state of New York, most Interstate Highways use sequential exit numbering (with some exceptions).[73][*[needs update](https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Dates_and_numbers#Chronological_items)*]

### Business routes

Standard Interstate shields

Markers for Business Loop Interstate 80 (left) and Business Spur Interstate 80 (right)

AASHTO defines a category of special routes separate from primary and auxiliary Interstate designations. These routes do not have to comply to Interstate construction or limited-access standards but are routes that may be identified and approved by the association. The same route marking policy applies to both US Numbered Highways and Interstate Highways; however, [business route](/source/Business_route) designations are sometimes used for Interstate Highways.[74] Known as [Business Loops and Business Spurs](/source/List_of_business_routes_of_the_Interstate_Highway_System), these routes principally travel through the corporate limits of a city, passing through the central business district when the regular route is directed around the city. They also use a green shield instead of the red and blue shield.[74] An example would be [Business Loop Interstate 75](/source/Interstate_75_Business_(Pontiac%2C_Michigan)) at [Pontiac, Michigan](/source/Pontiac%2C_Michigan), which follows surface roads into and through downtown. Sections of BL I-75's routing had been part of [US 10](/source/U.S._Route_10_in_Michigan) and [M-24](/source/M-24_(Michigan_highway)), predecessors of [I-75](/source/Interstate_75_in_Michigan) in the area.

## Financing

[I‑787](/source/Interstate_787) in [Watervliet](/source/Watervliet%2C_New_York), New York, showing the exit 8 [diamond interchange](/source/Diamond_interchange)

Interstate Highways and their rights-of-way are owned by the state in which they were built. The last federally owned portion of the Interstate System was the [Woodrow Wilson Bridge](/source/Woodrow_Wilson_Bridge) on the [Washington Capital Beltway](/source/Interstate_495_(Capital_Beltway)). The new bridge was completed in 2009 and is collectively owned by Virginia and Maryland.[75] Maintenance is generally the responsibility of the state department of transportation. However, there are some segments of Interstate owned and maintained by local authorities.

### Taxes and user fees

About 70 percent of the construction and maintenance costs of Interstate Highways in the United States have been paid through user fees, primarily the [fuel taxes](/source/Fuel_tax) collected by the federal, state, and local governments. To a much lesser extent, they have been paid for by tolls collected on [toll highways](/source/Toll_highway) and bridges. The federal gasoline tax was first imposed in 1932 at one cent per gallon; during the Eisenhower administration, the [Highway Trust Fund](/source/Highway_Trust_Fund), established by the Highway Revenue Act of 1956, set a three-cent-per-gallon fuel tax, which was then increased to 4.5 cents per gallon. Since 1993 the tax has remained at 18.4 cents per gallon.[76] Other excise taxes related to highway travel also accumulated in the Highway Trust Fund.[76] Initially, that fund was sufficient for the federal portion of building the Interstate system, built in the early years with "10 cent dollars", from the perspective of the states, as the federal government paid 90% of the costs while the state paid 10%. The system grew faster than the rates of fuel taxes and other driving-related taxes (e.g., excise taxes on tires).

The remaining costs of these highways are borne by general fund receipts, bond issues, designated property taxes, and other taxes. The federal contribution is funded primarily through [fuel taxes](/source/Fuel_tax) and through transfers from the Treasury's general fund.[5] Local government contributions are overwhelmingly from sources besides user fees.[77] As decades passed in the 20th century and into the 21st century, the portion of the user fees spent on highways themselves covers about 57 percent of their costs, with about one-sixth of the user fees being sent to other programs, including the [mass transit systems](/source/Mass_transit_system) in large cities. Some large sections of Interstate Highways that were planned or constructed before 1956 are still operated as toll roads, for example, the [Massachusetts Turnpike](/source/Massachusetts_Turnpike) (I-90), the [New York State Thruway](/source/New_York_State_Thruway) (I-87 and I-90), and [Kansas Turnpike](/source/Kansas_Turnpike) (I-35, I-335, I-470, I-70). Others have had their construction bonds paid off, and they have become toll-free, such as the [Connecticut Turnpike](/source/Connecticut_Turnpike) (I‑95, I-395), the [Richmond-Petersburg Turnpike](/source/Richmond-Petersburg_Turnpike) in Virginia (also I‑95), and the [Kentucky Turnpike](/source/Interstate_65_in_Kentucky#Kentucky_Turnpike) (I‑65).

A view of I-75 in Atlanta, Georgia, featuring [HOV lanes](/source/HOV_lane) running alongside the median

As American suburbs have expanded, the costs incurred in maintaining freeway infrastructure have also grown, leaving little in the way of funds for new Interstate construction.[78] This has led to the proliferation of toll roads (turnpikes) as the new method of building limited-access highways in suburban areas. Some Interstates are privately maintained (for example, the VMS company maintains I‑35 in Texas)[79] to meet rising costs of maintenance and allow state departments of transportation to focus on serving the fastest-growing regions in their states.

Parts of the Interstate System might have to be tolled in the future to meet maintenance and expansion demands, as has been done with adding toll [HOV](/source/High-occupancy_vehicle_lane)/[HOT lanes](/source/High-occupancy_toll_lane) in cities such as [Atlanta](/source/Atlanta), [Dallas](/source/Dallas), and [Los Angeles](/source/Los_Angeles).[*[further explanation needed](https://en.wikipedia.org/wiki/Wikipedia:Please_clarify)*] Although part of the tolling is an effect of the [SAFETEA‑LU](/source/SAFETEA%E2%80%91LU) act, which has put an emphasis on toll roads as a means to reduce congestion,[80][81] present federal law does not allow for a state to change a freeway section to a tolled section for all traffic.[82]

### Tolls

See also: [Category:Tolled sections of Interstate Highways](https://en.wikipedia.org/wiki/Category:Tolled_sections_of_Interstate_Highways)

An [I-76](/source/Interstate_76_(Ohio%E2%80%93New_Jersey)) trailblazer along the [Pennsylvania Turnpike](/source/Pennsylvania_Turnpike) with the black-on-yellow "Toll" sign

About 2,900 miles (4,700 km) of toll roads are included in the Interstate Highway System.[83] While federal legislation initially banned the collection of tolls on Interstates, many of the toll roads on the system were either completed or under construction when the Interstate Highway System was established. Since these highways provided logical connections to other parts of the system, they were designated as Interstate highways. [Congress](/source/United_States_Congress) also decided that it was too costly to either build toll-free Interstates parallel to these toll roads, or directly repay all the bondholders who financed these facilities and remove the tolls. Thus, these toll roads were [grandfathered](/source/Grandfather_clause) into the Interstate Highway System.[84]

Toll roads designated as Interstates (such as the [Massachusetts Turnpike](/source/Massachusetts_Turnpike)) were typically allowed to continue collecting tolls, but are generally ineligible to receive federal funds for maintenance and improvements. Some toll roads that did receive federal funds to finance emergency repairs (notably the [Connecticut Turnpike](/source/Connecticut_Turnpike) (I-95) following the [Mianus River Bridge](/source/Mianus_River_Bridge) collapse) were required to remove tolls as soon as the highway's construction bonds were paid off. In addition, these toll facilities were grandfathered from [Interstate Highway standards](/source/Interstate_Highway_standards). A notable example is the western approach to the [Benjamin Franklin Bridge](/source/Benjamin_Franklin_Bridge) in [Philadelphia](/source/Philadelphia), where [I-676](/source/Interstate_676) has a surface street section through a historic area.

Policies on toll facilities and Interstate Highways have since changed. The [Federal Highway Administration](/source/Federal_Highway_Administration) has allowed some states to collect tolls on existing Interstate Highways, while a recent extension of [I-376](/source/Interstate_376) included a section of [Pennsylvania Route 60](/source/Pennsylvania_Route_60) that was tolled by the [Pennsylvania Turnpike Commission](/source/Pennsylvania_Turnpike_Commission) before receiving Interstate designation. Also, newer toll facilities (like the tolled section of I-376, which was built in the early 1990s) must conform to Interstate standards. A new addition of the *[Manual on Uniform Traffic Control Devices](/source/Manual_on_Uniform_Traffic_Control_Devices)* in 2009 requires a black-on-yellow "Toll" sign to be placed above the Interstate trailblazer on Interstate Highways that collect tolls.[85]

Legislation passed in 2005 known as [SAFETEA-LU](/source/SAFETEA-LU) encouraged states to construct new Interstate Highways through "innovative financing" methods. SAFETEA-LU facilitated states to pursue innovative financing by easing the restrictions on building interstates as toll roads, either through state agencies or through [public–private partnerships](/source/Public%E2%80%93private_partnership). However, SAFETEA-LU left in place a prohibition of installing tolls on existing toll-free Interstates, and states wishing to toll such routes to finance upgrades and repairs must first seek approval from Congress. Many states have started using [High-occupancy toll lane](/source/High-occupancy_toll_lane) and other partial tolling methods, whereby certain lanes of highly congested freeways are tolled, while others are left free, allowing people to pay a fee to travel in less congested lanes. Examples of recent projects to add HOT lanes to existing freeways include the [Virginia HOT lanes](/source/Virginia_HOT_lanes) on the Virginia portions of the [Capital Beltway](/source/Capital_Beltway) and other related interstate highways (I-95, I-495, I-395) and the addition of express toll lanes to [Interstate 77 in North Carolina](/source/Interstate_77_in_North_Carolina) in the [Charlotte metropolitan area](/source/Charlotte_metropolitan_area).

### Chargeable and non-chargeable Interstate routes

Interstate Highways financed with federal funds are known as "chargeable" Interstate routes, and are considered part of the 42,000-mile (68,000 km) network of highways. Federal laws also allow "non-chargeable" Interstate routes, highways funded similarly to state and US Highways to be signed as Interstates, if they both meet the Interstate Highway standards and are logical additions or connections to the system.[86][87] These additions fall under two categories: routes that already meet Interstate standards, and routes not yet upgraded to Interstate standards. Only routes that meet Interstate standards may be signed as Interstates once their proposed number is approved, unless they are granted a design waiver by the [Federal Highway Administration](/source/Federal_Highway_Administration) (FHWA).[70]

## Signage

### Interstate shield

Several Interstate shield design proposals submitted by the Texas Highway Department

Interstate Highways are signed by a number placed on a red, white, and blue [sign](/source/Highway_shield). The shield design itself is a [registered trademark](/source/Registered_trademark) of the [American Association of State Highway and Transportation Officials](/source/American_Association_of_State_Highway_and_Transportation_Officials).[88] The colors red, white, and blue were chosen because they are the colors of the [American flag](/source/Flag_of_the_United_States). In the original design, the name of the state was displayed above the highway number, but in many states, this area is now left blank, allowing for the printing of larger and more-legible digits. Signs with the shield alone are placed periodically throughout each Interstate as [reassurance markers](/source/Reassurance_marker). These signs usually measure 36 inches (91 cm) high, and are 36 inches (91 cm) wide for two-digit Interstates or 45 inches (110 cm) for three-digit Interstates.[89]

Interstate business loops and spurs use a special shield in which the red and blue are replaced with green, the word "BUSINESS" appears instead of "INTERSTATE", and the word "SPUR" or "LOOP" usually appears above the number.[89] The green shield is employed to mark the main route through a city's central business district, which intersects the associated Interstate at one (spur) or both (loop) ends of the business route. The route usually traverses the main thoroughfare(s) of the city's downtown area or other major business district.[90] A city may have more than one Interstate-derived business route, depending on the number of Interstates passing through a city and the number of significant business districts therein.[91]

Over time, the design of the Interstate shield has changed. In 1957 the Interstate shield designed by [Texas Highway Department](/source/Texas_Highway_Department) employee Richard Oliver was introduced, the winner of a contest that included 100 entries;[92][93] at the time, the shield color was a dark navy blue and only 17 inches (43 cm) wide.[94] The *[Manual on Uniform Traffic Control Devices](/source/Manual_on_Uniform_Traffic_Control_Devices)* (MUTCD) standards revised the shield in the 1961,[95] 1971,[96] and 1978[97] editions.

### Exit numbering

For many years, California was the only state that did not use an exit numbering system. It was granted an exemption in the 1950s due to having an already largely completed and signed highway system; placing exit number signage across the state was deemed too expensive. To control costs, California began to incorporate exit numbers on its freeways in 2002—Interstate, US, and state routes alike. [Caltrans](/source/California_Department_of_Transportation) commonly installs exit number signage only when a freeway or interchange is built, reconstructed, retrofitted, or repaired, and it is usually tacked onto the top-right corner of an already existing sign. Newer signs along the freeways follow this practice as well. Most exits along California's Interstates now have exit number signage, particularly in rural areas. California, however, still does not use mileposts, although a few exist for experiments or for special purposes.[98][*[self-published source](https://en.wikipedia.org/wiki/Wikipedia:Verifiability#Self-published_sources)*]

On [I‑19](/source/Interstate_19) in [Arizona](/source/Arizona), length is measured in kilometers instead of miles because, at the time of construction, [a push for the United States to change](/source/Metrication_in_the_United_States) to a [metric system](/source/Metric_system) of measurement had gained enough traction that it was mistakenly assumed that all highway measurements would eventually be changed to metric (and some distance signs retain metric distances);[99] proximity to metric-using Mexico may also have been a factor, as I‑19 indirectly connects I‑10 to the [Mexican Federal Highway](/source/Mexican_Federal_Highway) system via surface streets in [Nogales](/source/Nogales%2C_Arizona).

Massachusetts converted its exit numbers in 2021, and most recently Rhode Island in 2022.[100]

### Sign locations

There are four common signage methods on Interstates:

- Locating a sign on the ground to the side of the highway, mostly the right, and is used to denote exits, as well as [rest areas](/source/Rest_area), motorist services such as gas and lodging, recreational sites, and freeway names

- Attaching the sign to an overpass

- Mounting on full [gantries](/source/Gantry_(road_sign)) that bridge the entire width of the highway and often show two or more signs

- Mounting on half-gantries that are located on one side of the highway, like a ground-mounted sign

## Statistics

Motor vehicles on I-95 in Miami

### Volume

- **Heaviest traveled**: 379,000 vehicles per day: [I-405](/source/Interstate_405_(California)) in Los Angeles, California (2011 estimate).[101]

### Elevation

- **Highest**: 11,158 feet (3,401 m): [I-70](/source/Interstate_70_in_Colorado) in the [Eisenhower Tunnel](/source/Eisenhower_Tunnel) at the [Continental Divide](/source/Continental_Divide_of_the_Americas) in the [Colorado](/source/Colorado) [Rocky Mountains](/source/Rocky_Mountains).[102]

- **Lowest (land)**: −52 feet (−16 m): [I-8](/source/Interstate_8) at the [New River](/source/New_River_(Mexico%E2%80%93United_States)) near [Seeley, California](/source/Seeley%2C_California).[102]

- **Lowest (underwater)**: −103 feet (−31 m): [I-95](/source/Interstate_95_in_Maryland) in the [Fort McHenry Tunnel](/source/Fort_McHenry_Tunnel) under the [Baltimore Inner Harbor](/source/Inner_Harbor).[103]

### Length

- **Longest (east–west)**: 3,020.54 miles (4,861.09 km): [I-90](/source/Interstate_90) from [Boston, Massachusetts](/source/Boston), to [Seattle, Washington](/source/Seattle).[104][105]

- **Longest (north–south)**: 1,908 mi (3,071 km): [I-95](/source/Interstate_95) from the [Canadian border](/source/Canada%E2%80%93United_States_border) near [Houlton, Maine](/source/Houlton%2C_Maine), to [Miami, Florida](/source/Miami).[104][42]

- **Shortest (two-digit)**: 1.40 mi (2.25 km): [I-69W](/source/Interstate_69W) in [Laredo, Texas](/source/Laredo%2C_Texas).[106]

- **Shortest (auxiliary)**: 0.70 mi (1.13 km): [I-878](/source/New_York_State_Route_878#Northern_segment) in [Queens](/source/Queens), [New York](/source/New_York_City), [New York](/source/New_York_(state)).[107][108]

- **Longest segment between state lines**: 877 mi (1,411 km): [I-10 in Texas](/source/Interstate_10_in_Texas) from the [New Mexico](/source/New_Mexico) state line near [El Paso](/source/El_Paso%2C_Texas) to the [Louisiana](/source/Louisiana) state line near [Orange, Texas](/source/Orange%2C_Texas).[109]

- **Shortest segment between state lines**: 453 ft (138 m): [I-95](/source/Interstate_95_in_the_District_of_Columbia)/[I-495](/source/Interstate_495_(Capital_Beltway)) (Capital Beltway) on the [Woodrow Wilson Bridge](/source/Woodrow_Wilson_Bridge) across the [Potomac River](/source/Potomac_River) where they briefly cross the southernmost tip of the [District of Columbia](/source/Washington%2C_DC) between its borders with [Maryland](/source/Maryland) and [Virginia](/source/Virginia).[105]

- **Longest concurrency**: 278.4 mi (448.0 km): [I-80](/source/Interstate_80) and [I-90](/source/Interstate_90); [Gary, Indiana](/source/Gary%2C_Indiana), to [Elyria, Ohio](/source/Elyria%2C_Ohio).[110]

### States

- **Most states served by an Interstate**: 15 states plus the District of Columbia: [I-95](/source/Interstate_95) through [Florida](/source/Interstate_95_in_Florida), [Georgia](/source/Interstate_95_in_Georgia), [South Carolina](/source/Interstate_95_in_South_Carolina), [North Carolina](/source/Interstate_95_in_North_Carolina), [Virginia](/source/Interstate_95_in_Virginia), [DC](/source/Interstate_95_in_the_District_of_Columbia), [Maryland](/source/Interstate_95_in_Maryland), [Delaware](/source/Interstate_95_in_Delaware), [Pennsylvania](/source/Interstate_95_in_Pennsylvania), [New Jersey](/source/Interstate_95_in_New_Jersey), [New York](/source/Interstate_95_in_New_York), [Connecticut](/source/Interstate_95_in_Connecticut), [Rhode Island](/source/Interstate_95_in_Rhode_Island), [Massachusetts](/source/Interstate_95_in_Massachusetts), [New Hampshire](/source/Interstate_95_in_New_Hampshire), and [Maine](/source/Interstate_95_in_Maine).[104]

- **Most Interstates in a state**: 32 routes: New York, totaling 1,750.66 mi (2,817.41 km)[111]

- **Most primary Interstates in a state**: 13 routes: Illinois[b][111]

- **Most Interstate mileage in a state**: 3,233.45 mi (5,203.73 km): Texas, in 17 different routes.[104]

- **Fewest Interstates in a state**: 3 routes: Delaware, New Mexico, North Dakota, and Rhode Island. Puerto Rico also has 3 routes.[111]

- **Fewest primary Interstates in a state**: 1 route: Delaware, Maine, and Rhode Island (I-95 in each case).[111]

- **Least Interstate mileage in a state**: 40.61 mi (65.36 km): Delaware, in 3 different routes.[111]

## Impact and reception

Following the passage of the Federal Aid Highway Act of 1956, passenger rail declined sharply as did freight rail for a short time, but the trucking industry expanded dramatically and the cost of shipping and travel fell sharply.[112][*[citation needed](https://en.wikipedia.org/wiki/Wikipedia:Citation_needed)*] [Suburbanization](/source/Suburbanization) became possible, with the rapid growth of larger, sprawling, and more car-dependent housing than was available in central cities, enabling [racial segregation](/source/Racial_segregation) by [white flight](/source/White_flight).[113][114][115] A sense of isolationism developed in suburbs, with suburbanites wanting to keep urban areas disconnected from the suburbs.[113] Tourism dramatically expanded, creating a demand for more service stations, motels, restaurants and visitor attractions. The Interstate System was the basis for urban expansion in the Sun Belt, and many urban areas in the region are thus very car-dependent.[116] The highways may have contributed to increased economic productivity in, and thereby increased migration to, the [Sun Belt](/source/Sun_Belt).[117] In rural areas, towns and small cities off the grid lost out as shoppers followed the interstate and new factories were located near them.[118]

### Effects on transport of goods

The system had a profound effect on interstate shipping. The Interstate Highway System was being constructed at the same time as the [intermodal shipping container](/source/Intermodal_container) made its debut. These containers could be placed on trailers behind trucks and shipped across the country with ease. A new road network and shipping containers that could be easily moved from ship to train to truck, meant that overseas manufacturers and domestic startups could get their products to market quicker than ever, allowing for accelerated economic growth.[119] Forty years after its construction, the Interstate Highway system returned on investment, making $6[*[among whom?](https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Words_to_watch#Unsupported_attributions)*] for every $1 spent on the project.[120][*[better source needed](https://en.wikipedia.org/wiki/Wikipedia:Verifiability#Questionable_sources)*] According to research by the [FHWA](/source/Federal_Highway_Administration), "from 1950 to 1989, approximately one-quarter of the nation's productivity increase is attributable to increased investment in the highway system."[121]

The system had a particularly strong effect in Southern states. The new system facilitated the relocation of heavy manufacturing to the South and spurred the development of Southern-based corporations like [Walmart](/source/Walmart) (in Arkansas) and [FedEx](/source/FedEx) (in Tennessee).[119]

The Interstate Highway System also dramatically affected American culture, contributing to cars becoming more central to the American identity. Before, driving was considered an excursion that required some amount of skill and could have some chance of unpredictability. With the standardization of signs, road widths and rules, certain unpredictabilities lessened. Justin Fox wrote, "By making road more reliable and by making Americans more reliant on them, they took away most of the adventure and romance associated with driving."[119]

### Urban decline and displacement of racial minorities

The Interstate Highway System has been criticized for contributing to the decline of some cities that were divided by Interstates, and for displacing minority neighborhoods in urban centers.[3] Between 1957 and 1977, the Interstate System alone displaced over 475,000 households and one million people across the country.[4] Highways have also been criticized for increasing racial segregation by creating physical barriers between neighborhoods,[122] and for overall reductions in available housing and population in neighborhoods affected by highway construction.[123] Other critics have blamed the Interstate Highway System for the decline of [public transportation in the United States](/source/Public_transportation_in_the_United_States) since the 1950s,[124] which minorities and low-income residents are three to six times more likely to use.[125] Previous highways, such as [US 66](/source/U.S._Route_66), were also bypassed by the new Interstate system, turning countless rural communities along the way into ghost towns.[126] The Interstate System has also contributed to continued resistance against new public transportation.[113]

The Interstate Highway System had a negative impact on minority groups, especially in urban areas. Even though the government used [eminent domain](/source/Eminent_domain_in_the_United_States) to obtain land for the Interstates, it was still economical to build where land was cheapest. This cheap land was often located in predominately minority areas.[116] Not only were minority neighborhoods destroyed, but in some cities the Interstates were used to divide white and minority neighborhoods.[113] These practices were common in cities both in the North and South, including [Nashville](/source/Nashville%2C_Tennessee), [Miami](/source/Miami), [Chicago](/source/Chicago), [Detroit](/source/Detroit), and many other cities. The division and destruction of neighborhoods led to the limitation of employment and other opportunities, which deteriorated the economic fabric of neighborhoods.[125]

### Health impacts

Neighborhoods bordering Interstates have a much higher level of particulate [air pollution](/source/Air_pollution_in_the_United_States) and are more likely to be chosen for polluting industrial facilities.[125] An [ABC News](/source/ABC_News_(United_States)) analysis in 2023 of data from the [Environmental Protection Agency](/source/Environmental_protection_agency_(United_States)) and the [Centers for Disease Control and Prevention](/source/Centers_for_Disease_Control_and_Prevention) found that neighborhoods within one mile of interstate highways had asthma rates 8% higher than the national average, and the lifetime cancer risk in neighborhoods closest to interstate highways was 3 times higher than in neighborhoods furthest away.[8] The elevated disease rates were attributed to exposure to [benzene](/source/Benzene), [formaldehyde](/source/Formaldehyde), and [hydrocarbons](/source/Hydrocarbon) associated with [vehicle fuel](/source/Vehicle_fuel).[8]

## See also

- [U.S. Roads portal](https://en.wikipedia.org/wiki/Portal:U.S._Roads)

- [Highway systems by country](/source/Highway_systems_by_country)

- [List of controlled-access highway systems](/source/List_of_controlled-access_highway_systems)

- [Non-motorized access on freeways](/source/Non-motorized_access_on_freeways)

## Notes

1. **[^](#cite_ref-3)** As of 2022[\[update\]](https://en.wikipedia.org/w/index.php?title=Interstate_Highway_System&action=edit).[2]

1. **[^](#cite_ref-113)** This counts the suffixed routes in Texas ([I-35E](/source/I-35E_(Texas)), [I-35W](/source/I-35W_(Texas)), [I-69E](/source/I-69E), [I-69C](/source/I-69C), and [I-69W](/source/I-69W)) as auxiliary routes or parts of the same primary Interstate and not separate primary Interstates.

## References

1. **[^](#cite_ref-FAHA56_1-0)** Weingroff, Richard F. (Summer 1996). ["Federal-Aid Highway Act of 1956, Creating the Interstate System"](https://web.archive.org/web/20120307133751/http://www.fhwa.dot.gov/publications/publicroads/96summer/p96su10.cfm). *Public Roads*. Vol. 60, no. 1. [ISSN](/source/ISSN_(identifier)) [0033-3735](https://search.worldcat.org/issn/0033-3735). Archived from [the original](https://highways.dot.gov/public-roads/summer-1996/federal-aid-highway-act-1956-creating-interstate-system) on March 7, 2012. Retrieved March 16, 2012.

1. ^ [***a***](#cite_ref-hm20_2-0) [***b***](#cite_ref-hm20_2-1) Office of Highway Policy Information (January 12, 2024). [*Table HM-20: Public Road Length, 2022, Miles By Functional System*](https://www.fhwa.dot.gov/policyinformation/statistics/2022/hm20.cfm) (Report). Federal Highway Administration. Retrieved August 14, 2024.

1. ^ [***a***](#cite_ref-StrombergVox_4-0) [***b***](#cite_ref-StrombergVox_4-1) Stromberg, Joseph (May 11, 2016). ["Highways Gutted American Cities. So Why Did They Build Them?"](https://www.vox.com/2015/5/14/8605917/highways-interstate-cities-history). *Vox*. [Archived](https://web.archive.org/web/20190425175726/https://www.vox.com/2015/5/14/8605917/highways-interstate-cities-history) from the original on April 25, 2019. Retrieved May 10, 2019.

1. ^ [***a***](#cite_ref-GamboaNBC_5-0) [***b***](#cite_ref-GamboaNBC_5-1) Gamboa, Suzanne; McCausland, Phil; Lederman, Josh; Popken, Ben (June 18, 2021). ["Bulldozed and bisected: Highway construction built a legacy of inequality"](https://www.nbcnews.com/specials/america-highways-inequality/). NBC News. [Archived](https://web.archive.org/web/20230624054418/https://www.nbcnews.com/specials/america-highways-inequality/) from the original on June 24, 2023. Retrieved June 18, 2023.

1. ^ [***a***](#cite_ref-ShirleyCBO_6-0) [***b***](#cite_ref-ShirleyCBO_6-1) Shirley, Chad (2023). [Testimony on the Status of the Highway Trust Fund: 2023 Update](https://www.cbo.gov/publication/59634) (Report). Congressional Budget Office. [Archived](https://web.archive.org/web/20240330144952/https://www.cbo.gov/publication/59634) from the original on March 30, 2024. Retrieved March 30, 2024.

1. **[^](#cite_ref-7)** Office of Highway Policy Information (February 5, 2024). [*Table VM-1: Annual Vehicle Distance Traveled in Miles and Related Data, 2022, by Highway Category and Vehicle Type*](https://www.fhwa.dot.gov/policyinformation/statistics/2022/vm1.cfm) (Report). Federal Highway Administration. [Archived](https://web.archive.org/web/20240924004830/https://www.fhwa.dot.gov/policyinformation/statistics/2022/vm1.cfm) from the original on September 24, 2024. Retrieved August 14, 2024.

1. **[^](#cite_ref-8)** National Center for Statistics and Analysis (May 2024). [Early Estimates of Motor Vehicle Traffic Fatalities and Fatality Rate by Sub-Categories in 2023](https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813581) (Report). National Highway Traffic Safety Administration. DOT HS 813 581. Retrieved August 14, 2024.

1. ^ [***a***](#cite_ref-Nichols_9-0) [***b***](#cite_ref-Nichols_9-1) [***c***](#cite_ref-Nichols_9-2) Nichols, Mark (September 20, 2023). ["Highway traffic pollution puts communities of color at greater health risk, data analysis shows"](https://abcnews.com/US/highway-traffic-pollution-puts-communities-color-greater-health/story?id=103340992). *ABC News*.

1. **[^](#cite_ref-10)** Schwantes, Carlos Arnaldo (2003). *Going Places: Transportation Redefines the Twentieth-Century West*. Bloomington: Indiana University Press. p. 142. [ISBN](/source/ISBN_(identifier)) [978-0-253-34202-7](https://en.wikipedia.org/wiki/Special:BookSources/978-0-253-34202-7).

1. ^ [***a***](#cite_ref-mehren_11-0) [***b***](#cite_ref-mehren_11-1) Mehren, E.J. (December 19, 1918). ["A Suggested National Highway Policy and Plan"](https://books.google.com/books?id=d7tCAQAAMAAJ&q=%22A+suggested+national+highway+policy+and+plan%22+Dec.+19+1918&pg=PA1109). *[Engineering News-Record](/source/Engineering_News-Record)*. Vol. 81, no. 25. pp. 1112–1117. [ISSN](/source/ISSN_(identifier)) [0891-9526](https://search.worldcat.org/issn/0891-9526). Retrieved August 17, 2015 – via [Google Books](/source/Google_Books).

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1. ^ [***a***](#cite_ref-Watson_article_on_Motor_Transport_convoy_13-0) [***b***](#cite_ref-Watson_article_on_Motor_Transport_convoy_13-1) [***c***](#cite_ref-Watson_article_on_Motor_Transport_convoy_13-2) Watson, Bruce (July–August 2020). ["Ike's Excellent Adventure"](https://www.americanheritage.com/ikes-excellent-adventure). *American Heritage*. Vol. 65, no. 4. [Archived](https://web.archive.org/web/20200709110417/https://www.americanheritage.com/ikes-excellent-adventure) from the original on July 9, 2020. Retrieved July 9, 2020.

1. **[^](#cite_ref-14)** Ambrose, Stephen (1983). *Eisenhower: Soldier, General of the Army, President-Elect (1893–1952)*. Vol. 1. New York: Simon & Schuster.[*[page needed](https://en.wikipedia.org/wiki/Wikipedia:Citing_sources)*]

1. ^ [***a***](#cite_ref-schwantes152_15-0) [***b***](#cite_ref-schwantes152_15-1) [Schwantes (2003)](#CITEREFSchwantes2003), p. 152.

1. **[^](#cite_ref-16)** McNichol, Dan (2006a). *The Roads That Built America: The Incredible Story of the U.S. Interstate System*. New York: Sterling. p. 87. [ISBN](/source/ISBN_(identifier)) [978-1-4027-3468-7](https://en.wikipedia.org/wiki/Special:BookSources/978-1-4027-3468-7).

1. **[^](#cite_ref-17)** [Schwantes (2003)](#CITEREFSchwantes2003), p. 153.

1. **[^](#cite_ref-18)** [McNichol (2006a)](#CITEREFMcNichol2006a), p. 78.

1. **[^](#cite_ref-19)** Weingroff, Richard F. (Summer 1996). ["The Federal-State Partnership at Work: The Concept Man"](https://web.archive.org/web/20100528132734/http://www.tfhrc.gov/pubrds/summer96/p96su7b.htm#9). *Public Roads*. Vol. 60, no. 1. [ISSN](/source/ISSN_(identifier)) [0033-3735](https://search.worldcat.org/issn/0033-3735). Archived from [the original](http://www.tfhrc.gov/pubrds/summer96/p96su7b.htm#9) on May 28, 2010. Retrieved March 16, 2012.

1. **[^](#cite_ref-20)** Mooney, Robert (September 19, 2023). ["Interstate System: Dwight D. Eisenhower National System of Interstate and Defense Highways"](https://www.fhwa.dot.gov/programadmin/interstate.cfm). Federal Highway Administration. Retrieved May 21, 2026.

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1. **[^](#cite_ref-23)** [Smith (2012)](#CITEREFSmith2012), pp. 652–653.

1. **[^](#cite_ref-24)** [Smith (2012)](#CITEREFSmith2012), pp. 651–654.

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1. ^ [***a***](#cite_ref-aashto_ho2_64-0) [***b***](#cite_ref-aashto_ho2_64-1) [***c***](#cite_ref-aashto_ho2_64-2) [***d***](#cite_ref-aashto_ho2_64-3) [***e***](#cite_ref-aashto_ho2_64-4) [***f***](#cite_ref-aashto_ho2_64-5) [American Association of State Highway and Transportation Officials](/source/American_Association_of_State_Highway_and_Transportation_Officials) (January 2000). ["Establishment of a Marking System of the Routes Comprising the National System of Interstate and Defense Highways"](https://web.archive.org/web/20061101234238/http://cms.transportation.org/sites/route/docs/HO2_Policy_Retention_HO1.pdf) (PDF). American Association of State Highway and Transportation Officials. Archived from [the original](http://cms.transportation.org/sites/route/docs/HO2_Policy_Retention_HO1.pdf) (PDF) on November 1, 2006. Retrieved January 23, 2008.

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1. **[^](#cite_ref-rambler_20050118_67-0)** Weingroff, Richard F. (January 18, 2005). ["Was I-76 Numbered to Honor Philadelphia for Independence Day, 1776?"](https://www.fhwa.dot.gov/infrastructure/i76.cfm). *Ask the Rambler*. Federal Highway Administration. [Archived](https://web.archive.org/web/20130703012425/https://www.fhwa.dot.gov/infrastructure/i76.cfm) from the original on July 3, 2013. Retrieved January 17, 2008.

1. **[^](#cite_ref-fhwa-faq19_68-0)** Federal Highway Administration (n.d.). ["Interstate FAQ"](https://highways.dot.gov/highway-history/interstate-system/50th-anniversary/interstate-frequently-asked-questions). Federal Highway Administration. [Archived](https://web.archive.org/web/20130507121442/http://www.fhwa.dot.gov/interstate/faq.htm#question19) from the original on May 7, 2013. Retrieved June 26, 2009. Proposed I-41 in Wisconsin and partly completed I-74 in North Carolina respectively are possible and current exceptions not adhering to the guideline. It is not known if the US Highways with the same numbers will be retained in the states upon completion of the Interstate routes.

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1. **[^](#cite_ref-87)** [23 U.S.C.](/source/Title_23_of_the_United_States_Code) [§ 103(c)](https://www.law.cornell.edu/uscode/text/23/103(c)), Interstate System.

1. **[^](#cite_ref-88)** [Pub. L.](/source/Act_of_Congress#Public_law,_private_law,_designation) [99–599: Surface Transportation Assistance Act of 1978](https://uslaw.link/citation/us-law/public/99/599)

1. **[^](#cite_ref-89)** American Association of State Highway Officials (September 19, 1967). ["Trademark Registration 0835635"](https://web.archive.org/web/20130502074700/http://tsdr.uspto.gov/#caseNumber=72239199&caseType=SERIAL_NO&searchType=statusSearch). *Trademark Electronic Search System*. [United States Patent and Trademark Office](/source/United_States_Patent_and_Trademark_Office). Archived from [the original](http://tsdr.uspto.gov/#caseNumber=72239199&caseType=SERIAL_NO&searchType=statusSearch) on May 2, 2013. Retrieved April 27, 2014.

1. ^ [***a***](#cite_ref-SHS_90-0) [***b***](#cite_ref-SHS_90-1) Federal Highway Administration (May 10, 2005) [2004]. ["Guide Signs"](https://mutcd.fhwa.dot.gov/SHSe/Guide.pdf) (PDF). *Standard Highway Signs* (2004 English ed.). Washington, DC: Federal Highway Administration. pp. 3-1 to 3-3. [OCLC](/source/OCLC_(identifier)) [69678912](https://search.worldcat.org/oclc/69678912). [Archived](https://web.archive.org/web/20120205020037/http://mutcd.fhwa.dot.gov/SHSe/Guide.pdf) (PDF) from the original on February 5, 2012. Retrieved February 22, 2012.

1. **[^](#cite_ref-MUTCD2D_91-0)** Federal Highway Administration (December 2009). ["Chapter 2D. Guide Signs: Conventional Roads"](https://mutcd.fhwa.dot.gov/pdfs/2009/part2d.pdf) (PDF). [*Manual on Uniform Traffic Control Devices*](/source/Manual_on_Uniform_Traffic_Control_Devices) (2009 ed.). Washington, DC: Federal Highway Administration. p. 142. [OCLC](/source/OCLC_(identifier)) [496147812](https://search.worldcat.org/oclc/496147812). [Archived](https://web.archive.org/web/20120315132420/http://mutcd.fhwa.dot.gov/pdfs/2009/part2d.pdf) (PDF) from the original on March 15, 2012. Retrieved February 22, 2012.

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1. **[^](#cite_ref-102)** Hecox, Doug (August 1, 2019). ["New FHWA Report Reveals States with the Busiest Highways"](https://www.transportation.gov/briefing-room/new-fhwa-report-reveals-states-busiest-highways) (Press release). Federal Highway Administration. [Archived](https://web.archive.org/web/20220830111658/https://www.transportation.gov/briefing-room/new-fhwa-report-reveals-states-busiest-highways) from the original on August 30, 2022. Retrieved August 30, 2022.

1. ^ [***a***](#cite_ref-Interstate_Highway_System_Fact_Sheet_103-0) [***b***](#cite_ref-Interstate_Highway_System_Fact_Sheet_103-1) American Association of State Highway and Transportation Officials (n.d.). ["Interstate Highway Fact Sheet"](https://web.archive.org/web/20081010060935/http://www.interstate50th.org/docs/InterstateHighwayFactSheet.pdf) (PDF). American Association of State Highway and Transportation Officials. Archived from [the original](http://www.interstate50th.org/docs/InterstateHighwayFactSheet.pdf) (PDF) on October 10, 2008. Retrieved February 22, 2012.

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1. **[^](#cite_ref-110)** Transportation Planning and Programming Division (n.d.). ["Interstate Highway No. 10"](https://www.dot.state.tx.us/tpp/hwy/IH/IH0010.htm). *Highway Designation Files*. [Texas Department of Transportation](/source/Texas_Department_of_Transportation). Retrieved August 31, 2010.

1. **[^](#cite_ref-route-finder_111-0)** Price, Jeff (May 6, 2019). ["Table 1: Main Routes of the Dwight D. Eisenhower National System Of Interstate and Defense Highways as of December 31, 2018"](https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/table01.cfm). *Route Log and Finder List*. Federal Highway Administration. [Archived](https://web.archive.org/web/20120422220808/http://www.fhwa.dot.gov/reports/routefinder/table1.cfm) from the original on April 22, 2012. Retrieved June 21, 2021.

1. ^ [***a***](#cite_ref-fhwa_route_log_112-0) [***b***](#cite_ref-fhwa_route_log_112-1) [***c***](#cite_ref-fhwa_route_log_112-2) [***d***](#cite_ref-fhwa_route_log_112-3) [***e***](#cite_ref-fhwa_route_log_112-4) ["Table 3: Interstate Routes in Each of the 50 States, District of Columbia, and Puerto Rico"](https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/table03.cfm). *Route Log and Finder List*. Federal Highway Administration. [Archived](https://web.archive.org/web/20180711030748/https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/table03.cfm) from the original on July 11, 2018. Retrieved August 25, 2018.

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1. ^ [***a***](#cite_ref-:0_115-0) [***b***](#cite_ref-:0_115-1) [***c***](#cite_ref-:0_115-2) [***d***](#cite_ref-:0_115-3) Kruse, Kevin M. (August 14, 2019). ["How Segregation Caused Your Traffic Jam"](https://www.nytimes.com/interactive/2019/08/14/magazine/traffic-atlanta-segregation.html). *[The New York Times](/source/The_New_York_Times)*. [ISSN](/source/ISSN_(identifier)) [0362-4331](https://search.worldcat.org/issn/0362-4331). [Archived](https://web.archive.org/web/20231117205110/https://www.nytimes.com/interactive/2019/08/14/magazine/traffic-atlanta-segregation.html) from the original on November 17, 2023. Retrieved November 16, 2023.

1. **[^](#cite_ref-116)** Chiotakis, Steve (June 30, 2020). ["How freeways represent the racial divide in LA"](https://www.kcrw.com/news/shows/greater-la/robert-fuller-freeways-urbanism-race/la-freeways). KCRW. [Archived](https://web.archive.org/web/20231116022018/https://www.kcrw.com/news/shows/greater-la/robert-fuller-freeways-urbanism-race/la-freeways) from the original on November 16, 2023. Retrieved November 16, 2023.

1. **[^](#cite_ref-117)** Mahajan, Avichal (June 26, 2023). ["Highways and segregation"](https://doi.org/10.1016%2Fj.jue.2023.103574). *Journal of Urban Economics*. **141** 103574. [doi](/source/Doi_(identifier)):[10.1016/j.jue.2023.103574](https://doi.org/10.1016%2Fj.jue.2023.103574). [S2CID](/source/S2CID_(identifier)) [259681981](https://api.semanticscholar.org/CorpusID:259681981).

1. ^ [***a***](#cite_ref-:1_118-0) [***b***](#cite_ref-:1_118-1) Allison, Robert J., ed. (2000). *American Social and Political Movements, 1945–2000: Pursuit of Liberty*. History in Dispute. Vol. 2. Detroit: St. James Press. [ISBN](/source/ISBN_(identifier)) [978-1-55862-396-5](https://en.wikipedia.org/wiki/Special:BookSources/978-1-55862-396-5).[*[page needed](https://en.wikipedia.org/wiki/Wikipedia:Citing_sources)*]

1. **[^](#cite_ref-119)** Glaeser, Edward L.; Tobio, Kristina (2007). *The Rise of the Sunbelt* (Report). Taubman Center Policy Briefs. PB-2007-5.

1. **[^](#cite_ref-120)** Blas, Elisheva (November 2010). ["The Dwight D. Eisenhower National System of Interstate and Defense Highways: The Road to Success?"](http://www.societyforhistoryeducation.org/pdfs/N10_NHD_Blas_Junior.pdf) (PDF). *The History Teacher*. Vol. 44, no. 1. Long Beach, California: Society for History Education. pp. 127–142. [ISSN](/source/ISSN_(identifier)) [0018-2745](https://search.worldcat.org/issn/0018-2745). [JSTOR](/source/JSTOR_(identifier)) [25799401](https://www.jstor.org/stable/25799401). [Archived](https://web.archive.org/web/20170402233423/http://www.societyforhistoryeducation.org/pdfs/N10_NHD_Blas_Junior.pdf) (PDF) from the original on April 2, 2017. Retrieved April 27, 2017.

1. ^ [***a***](#cite_ref-fox1_121-0) [***b***](#cite_ref-fox1_121-1) [***c***](#cite_ref-fox1_121-2) Fox, Justin (January 26, 2004). ["The Great Paving: How the Interstate Highway System Helped Create the Modern Economy—and Reshaped the Fortune 500"](https://web.archive.org/web/20180601030412/http://archive.fortune.com/magazines/fortune/fortune_archive/2004/01/26/358835/index.htm). *Fortune*. Archived from [the original](https://money.cnn.com/magazines/fortune/fortune_archive/2004/01/26/358835/index.htm) on June 1, 2018. Retrieved May 10, 2019.

1. **[^](#cite_ref-Cox_&_Love_122-0)** Cox, Wendell; Jean, Love (June 1996). [*40 Years of the US Interstate Highway System: An Analysis The Best Investment A Nation Ever Made*](http://www.publicpurpose.com/freeway1.htm). American Highway Users Alliance. [Archived](https://web.archive.org/web/20221121185957/http://www.publicpurpose.com/freeway1.htm) from the original on November 21, 2022. Retrieved November 21, 2022 – via Public Purpose.

1. **[^](#cite_ref-123)** Phelps, Haley (2021). ["When Interstates Paved the Way"](https://www.richmondfed.org/publications/research/econ_focus/2021/q2-3/economic_history#:~:text=According%20to%20research%20by%20the,market%20for%20goods%20as%20firms). Federal Reserve Bank of Richmond. [Archived](https://web.archive.org/web/20230307231408/https://www.richmondfed.org/publications/research/econ_focus/2021/q2-3/economic_history) from the original on March 7, 2023. Retrieved May 17, 2024.

1. **[^](#cite_ref-124)** Miller, Johnny (February 21, 2018). ["Roads to Nowhere: How Infrastructure Built on American Inequality"](https://www.theguardian.com/cities/2018/feb/21/roads-nowhere-infrastructure-american-inequality). *The Guardian*. London. [Archived](https://web.archive.org/web/20210404202301/https://www.theguardian.com/cities/2018/feb/21/roads-nowhere-infrastructure-american-inequality) from the original on April 4, 2021. Retrieved April 3, 2021.

1. **[^](#cite_ref-125)** Nall, Clayton; O'Keeffe, Zachary P. (2018). ["What Did Interstate Highways Do to Urban Neighborhoods?"](http://www.nallresearch.com/uploads/7/9/1/7/7917910/urbanhighways.pdf) (PDF). *Nall Research*. p. 30. [Archived](https://web.archive.org/web/20210403042929/http://www.nallresearch.com/uploads/7/9/1/7/7917910/urbanhighways.pdf) (PDF) from the original on April 3, 2021. Retrieved March 17, 2022.

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1. ^ [***a***](#cite_ref-:2_127-0) [***b***](#cite_ref-:2_127-1) [***c***](#cite_ref-:2_127-2) Fitzgerald, Joan; Agyeman, Julian (September 7, 2021). ["Removing urban highways can improve neighborhoods blighted by decades of racist policies"](https://theconversation.com/removing-urban-highways-can-improve-neighborhoods-blighted-by-decades-of-racist-policies-166220). *The Conversation*. [Archived](https://web.archive.org/web/20231204234127/http://theconversation.com/removing-urban-highways-can-improve-neighborhoods-blighted-by-decades-of-racist-policies-166220) from the original on December 4, 2023. Retrieved December 4, 2023.

1. **[^](#cite_ref-128)** Schulten, Susan (2018). [*A History of America in 100 Maps*](https://books.google.com/books?id=2g1uDwAAQBAJ&dq=how+many+small+towns+on+route+66+fell+into+decline+after+the+interstate&pg=PA229). University of Chicago Press. p. 229. [ISBN](/source/ISBN_(identifier)) [978-0-226-45861-8](https://en.wikipedia.org/wiki/Special:BookSources/978-0-226-45861-8).

## Further reading

- Arcadi, Teal (2022). "Partisanship and Permanence: How Congress Contested the Origins of the Interstate Highway System and the Future of American Infrastructure". *Modern American History*. Vol. 5. pp. 53–77. [doi](/source/Doi_(identifier)):[10.1017/mah.2022.4](https://doi.org/10.1017%2Fmah.2022.4).

- Browning, Edgar A (2011). *Roadbuilding Construction Equipment at Work: Building the Interstate Highways through New England's Green Mountains*. Icongrafix. [ISBN](/source/ISBN_(identifier)) [978-1-58388-277-1](https://en.wikipedia.org/wiki/Special:BookSources/978-1-58388-277-1).

- Friedlaender, Ann Fetter (1965). [*The Interstate Highway System. A Study in Public Investment*](https://archive.org/details/interstatehighwa0000frie). Amsterdam: North-Holland Publishing. [OCLC](/source/OCLC_(identifier)) [498010](https://search.worldcat.org/oclc/498010).

- Hanlon, Martin D. (1997). *You Can Get There from Here: How the Interstate Highways Transformed America*. New York: Basingstoke. [ISBN](/source/ISBN_(identifier)) [978-0-312-12909-5](https://en.wikipedia.org/wiki/Special:BookSources/978-0-312-12909-5).

- Lewis, Tom (1997). [*Divided Highways: Building the Interstate Highways, Transforming American Life*](https://archive.org/details/dividedhighwaysb00lewi). New York: Viking. [ISBN](/source/ISBN_(identifier)) [978-0-670-86627-4](https://en.wikipedia.org/wiki/Special:BookSources/978-0-670-86627-4).

- Lichter, Daniel T.; Fuguitt, Glenn V. (December 1980). "Demographic Response to Transportation Innovation: The Case of the Interstate Highway". *Social Forces*. Vol. 59, no. 2. pp. 492–512. [doi](/source/Doi_(identifier)):[10.1093/sf/59.2.492](https://doi.org/10.1093%2Fsf%2F59.2.492). [JSTOR](/source/JSTOR_(identifier)) [2578033](https://www.jstor.org/stable/2578033).

- Rose, Mark H. (1990). *Interstate: Express Highway Politics 1939–1989*. Knoxville: University of Tennessee Press. [ISBN](/source/ISBN_(identifier)) [978-0-87049-671-4](https://en.wikipedia.org/wiki/Special:BookSources/978-0-87049-671-4).

## External links

**[KML file](https://en.wikipedia.org/w/index.php?title=Template:Attached_KML/Interstate_Highway_System&action=raw)** ([edit](https://en.wikipedia.org/w/index.php?title=Template:Attached_KML/Interstate_Highway_System&action=edit) · [help](https://en.wikipedia.org/wiki/Help:Attached_KML))

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KML is from Wikidata

Wikimedia Commons has media related to [Interstate Highway System](https://commons.wikimedia.org/wiki/Category:Interstate_Highway_System).

[Wikisource](/source/Wikisource) has original text related to this article:

***[Highways for the National Defense](https://en.wikisource.org/wiki/Highways_for_the_National_Defense)***

***[Highway Needs of the National Defense](https://en.wikisource.org/wiki/Highway_Needs_of_the_National_Defense)***

- Geographic data related to [Interstate Highway System](https://www.openstreetmap.org/relation/9714600) at [OpenStreetMap](/source/OpenStreetMap)

- [Dwight D. Eisenhower National System of Interstate and Defense Highways](https://www.fhwa.dot.gov/programadmin/interstate.cfm), Federal Highway Administration (FHWA)

- [Route Log and Finder List](https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/index.cfm), FHWA

- [State-by-state maps of the National Highway System](https://www.fhwa.dot.gov/planning/national_highway_system/nhs_maps/) of the FHWA include Interstate highways

- [Turner-Fairbank Highway Research Center](https://highways.dot.gov/turner-fairbank-highway-research-center), FHWA

- [Interstate Highway System](https://www.eisenhowerlibrary.gov/research/online-documents/interstate-highway-system), Dwight D. Eisenhower Presidential Library and Museum

- ["Keep on Trucking?: Would you pay more in taxes to fix roads and rail?"](https://web.archive.org/web/20090829224806/http://www.pbs.org/now/shows/535/index.html), *NOW* on PBS

v t e Primary Interstate Highways Signed 2 4 5 8 10 11 12 14 15 16 17 19 20 22 24 25 26 27 29 30 31 35 37 39 40 41 42 43 44 45 49 55 57 59 64 65 66 KS–KY VA–DC 68 69 70 71 72 73 74 75 76 CO–NE OH–NJ 77 78 79 80 81 82 WA–OR PA–NY CT–RI 83 84 OR–UT PA–MA 85 86 ID PA–NY CT–MA 87 NC NY 88 IL NY 89 90 91 93 94 95 96 97 99 H-1 H-2 H-3 Unsigned A-1 A-2 A-3 A-4 PRI-1 PRI-2 PRI-3 Lists Primary Auxiliary Suffixed Business Future Other Standards Gaps Tolled Routes in italics are no longer a part of the system. Major Interstates are highlighted.

v t e Numbered highways in the United States National systems Interstate Highway System U.S. Numbered Highway System State highways Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming Other areas American Samoa District of Columbia Guam Northern Mariana Islands Puerto Rico Virgin Islands

v t e Route designations in the United States Multistate systems Interstate U.S. Highway Intrastate systems Toll road State highway County highway Farm-to-market road Special route types Alternate route Business/city route Bypass route Divided route Emergency detour route Loop route Scenic route Spur route Other U.S. Bicycle Route Forest highway Indian route Territorial highway Related National Highway System

v t e Dwight D. Eisenhower 34th President of the United States (1953–1961) Supreme Allied Commander Europe (1951–1952) Chief of Staff of the Army (1945–1948) Commander, Supreme Headquarters Allied Expeditionary Force (1943–1945) Military career Military career 1919 Motor Transport Corps convoy Louisiana Maneuvers Operation Torch European Theater of Operations Allied invasion of Sicily Armistice of Cassibile June 6, 1944, order of the day People of Western Europe speech Normandy landings Operation Veritable Berlin Declaration Military Governor, U.S. Occupation Zone in Germany Disarmed Enemy Forces European Advisory Commission Supreme Commander of NATO, 1951-1952 Presidency (timeline) Transition 1953 inauguration 1957 inauguration State of the Union Address 1953 1954 1955 1956 1957 1958 1959 1960 1961 Cabinet Judicial appointments Supreme Court Farewell address "Military–industrial complex" Kennedy transition Executive Orders Presidential Proclamations Foreign policy Eisenhower Doctrine Korean War 1953; Korean Armistice Agreement 1953 Iranian coup d'état "Chance for Peace" speech (1953) Cold War Domino theory Khrushchev, Eisenhower and De-Stalinization New Look policy Massive retaliation 1955 Geneva Summit 1960 U-2 incident Atomic Energy Act of 1954 Atoms for Peace Restricted Data Agricultural Trade Development and Assistance Act of 1954 Food for Peace Suez Crisis (1956) DARPA (1958) EURATOM Cooperation Act of 1958 National Aeronautics and Space Act 1958; NASA Operation 40 (1960) Domestic policy Executive Order 10479 (1953) Outer Continental Shelf Act (1953) Refugee Relief Act (1953) Submerged Lands Act (1953) U.S. Department of Health, Education, and Welfare (1953) Agricultural Act of 1954 National Wool Act of 1954 Special Milk Program Excise Tax Reduction Act of 1954 Internal Revenue Code of 1954 Watershed Protection and Flood Prevention Act of 1954 Small Watershed Program Air Pollution Control Act of 1955 Agricultural Act of 1956 Soil Bank Act Soil Bank Program Federal Voting Assistance Program (1955) Bank Holding Company Act (1956) Federal-Aid Highway Act of 1956 Interstate Highway System Highway Trust Fund Fish and Wildlife Act (1956) People to People Student Ambassador Program (1956) President's Council on Physical Fitness and Sports (1956) Civil Rights Act of 1957 U.S. Commission on Civil Rights U.S. Department of Justice Civil Rights Division Federal Plant Pest Act of 1957 Little Rock Nine intervention (1957) Price–Anderson Nuclear Industries Indemnity Act (1957) Alaska Statehood Act (1958) Humane Slaughter Act (1958) National Defense Education Act 1958; Federal Perkins Loan Student loans in the United States Hawaii Admission Act (1959) Multiple-Use Sustained-Yield Act of 1960 Civil Rights Act of 1960 Sikes Act (1960) Books Crusade in Europe (1948) Elections Primaries Draft Eisenhower movement 1948 1952 1956 Republican National Conventions 1952 Vice presidential candidate selection Logistics Television broadcasts 1956 General elections 1952 1956 Legacy Bibliography Birthplace Eisenhower Presidential Library, Museum, gravesite Boyhood home Eisenhower National Historic Site, home and farm Eisenhower House Dwight D. Eisenhower Memorial Eisenhower Executive Office Building Wichita Dwight D. Eisenhower National Airport Eisenhower Fellowships Eisenhower Institute Eisenhower Monument Eisenhower dollar Eisenhower Centennial silver dollar U.S. Postage stamps Dwight D. Eisenhower Army Medical Center Eisenhower Medical Center Eisenhower Trophy Eisenhower Tunnel Eisenhower Golf Club Eisenhower Theater Statue of Dwight D. Eisenhower (U.S. Capitol) Fort Eisenhower Mount Eisenhower White House putting green Eisenhower College Places named for Eisenhower Other tributes and memorials Popular culture Eisenhower jacket Eisenhower Tree Crusade in Europe (1949 television series) Backstairs at the White House (1979 miniseries) Ike (1979 miniseries) Ike: Countdown to D-Day (2004 film) Pressure (2014 play) Family Mary "Mamie" Geneva Doud Eisenhower (wife) John Eisenhower (son) David Eisenhower (grandson) Anne Eisenhower (granddaughter) Susan Eisenhower (granddaughter) Mary Jean Eisenhower (granddaughter) Jennie Eisenhower (great-granddaughter) Ida Stover Eisenhower (mother) Arthur Eisenhower (brother) Edgar N. Eisenhower (brother) Roy Eisenhower (brother) Earl D. Eisenhower (brother) Milton S. Eisenhower (brother) Related Eisenhower baseball controversy Camp David "And I don't care what it is" Atoms for Peace Award Introduction to Outer Space Eddie Slovik Kay Summersby ← Harry S. Truman John F. Kennedy → Category

v t e United States federal transportation legislation Federal aid highway acts 1916 1921 1944 1952 1956 1968 1973 1974 Surface transportation authorization acts 1978 1982 1987 Intermodal Surface Transportation Efficiency Act (ISTEA) National Highway System Designation Act of 1995 Transportation Equity Act for the 21st Century (TEA-21) Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) Moving Ahead for Progress in the 21st Century Act (MAP-21) Fixing America's Surface Transportation Act (FAST Act) Infrastructure Investment and Jobs Act (IIJA) Public transit 1964 1965 1970 1974 Related Federal-aid highway program Highway Beautification Act Highway Trust Fund Interstate Highway System National Traffic and Motor Vehicle Safety Act United States Department of Transportation (USDOT)

Authority control databases National United States Israel Other NARA Yale LUX

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Adapted from the Wikipedia article [Interstate Highway System](https://en.wikipedia.org/wiki/Interstate_Highway_System) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Interstate_Highway_System?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.