 Interstate 40 | |
|---|---|
 | |
| Route information | |
| Length | 2,556.61 mi[1] (4,114.46 km) |
| Existed | August 14, 1957[2]–present |
| NHS | Entire route |
| Major junctions | |
| West end |  I-15 inBarstow, CA |
| Major intersections | |
| East end |   US 117 /NC 132 inWilmington, NC |
| Location | |
| Country | United States |
| States | California,Arizona,New Mexico,Texas,Oklahoma,Arkansas,Tennessee,North Carolina |
| Highway system | |
Interstate 40 (I-40) is a major east–west transcontinentalInterstate Highway in thesoutheastern andsouthwestern portions of the United States. At a length of 2,556.61 miles (4,114.46 km), it is the third-longest Interstate Highway in the country, afterI-90 andI-80. From west to east, it passes throughCalifornia,Arizona,New Mexico,Texas,Oklahoma,Arkansas,Tennessee, andNorth Carolina. Its western terminus is atI-15 inBarstow, California, while its eastern terminus is at aconcurrency withU.S. Route 117 (US 117) andNorth Carolina Highway 132 (NC 132) inWilmington, North Carolina. Major cities served by the Interstate includeFlagstaff, Arizona;Albuquerque, New Mexico;Amarillo, Texas;Oklahoma City, Oklahoma;Fort Smith andLittle Rock in Arkansas;Memphis,Nashville, andKnoxville in Tennessee; andAsheville,Winston-Salem,Greensboro,Durham,Raleigh, and Wilmington in North Carolina.
I-40 begins in theMojave Desert in California, and then proceeds through theColorado Plateau in Arizona and the southern tip of theRocky Mountains in New Mexico. It then traverses theGreat Plains through theTexas Panhandle and Oklahoma, and passes south of theOzarks in Arkansas. The freeway crosses theAppalachian Mountains in Tennessee and North Carolina, before terminating in theAtlantic Coastal Plain near theAtlantic Ocean.
Much of the western part of I-40, from Barstow toOklahoma City, parallels or overlays the historicU.S. Route 66. East of Oklahoma City, the route generally parallelsUS 64 andUS 70. I-40 was established by theFederal-Aid Highway Act of 1956, and the numbering was subsequently approved on August 14, 1957, along with most of the rest of the system. The eastern terminus was initially planned to be located atI-85 in Greensboro, but theFederal Highway Administration later approved extending the route to its current eastern terminus in Wilmington. As a result, this was the last segment of I-40 to be completed upon its dedication in 1990.
| mi[1] | km | |
|---|---|---|
| CA | 154.61 | 248.82 |
| AZ | 359.48 | 578.53 |
| NM | 373.51 | 601.11 |
| TX | 177.10 | 285.01 |
| OK | 331.73 | 533.87 |
| AR | 284.69 | 458.16 |
| TN | 455.28 | 732.70 |
| NC | 420.21 | 676.26 |
| Total | 2,556.61 | 4,114.46 |
I-40 is the third-longest freeway in the United States, spanning 2,556.61 miles (4,114.46 km) across the southern half of the country. The longest stretch of the highway is in Tennessee, and the shortest is in California. The busiest stretch of I-40 is in Knoxville, concurrent withI-75, which has anannual average daily traffic volume of more than 210,000 vehicles.[3] The lowest traffic volumes are found on rural stretches in New Mexico, Texas, and Oklahoma, where the freeway carries fewer than 15,000 vehicles per day.[4][5][6]
I-40 in California crosses through the lightly populated northern part of theInland Empire region of the state. Its western end is inBarstow, California. Known as the Needles Freeway, it heads east from Barstow across theMojave Desert inSan Bernardino County toNeedles, before it crosses theColorado River intoArizona southwest ofKingman. I-40 covers 155 miles (249 km) in California. Some signs show thecontrol city for I-40 westbound to beLos Angeles, where drivers would followI-15 south from its western terminus in Barstow. The highway is four lanes for the entirety of its length in the state.
A sign in California showing the distance toWilmington, North Carolina, has been stolen several times.[7]
I-40 is a main route to the South Rim of theGrand Canyon, with the exits leading intoGrand Canyon National Park inWilliams and Flagstaff. I-40 covers 359 miles (578 km) in Arizona. Just west of exit 190, west of Flagstaff, is its highest elevation along I-40 in the US, as the road crosses just over 7,330 feet (2,230 m) at the Arizona Divide near milepost 190. I-40 also passes through theNavajo Nation, the largest Indian reservation in the US. Like California's segment, the highway is four lanes for the entirety of its length in the state.
I-40 covers 374 miles (602 km) in New Mexico. As in other states it parallels or overrides the post 1937 Route 66 route through the state. Notable cities along I-40 includeGallup,Grants,Albuquerque,Santa Rosa, andTucumcari. I-40 also travels through severalIndian reservations in the western half of the state. It reaches its highest point in the state of 7,275 feet (2,217 m) at the Continental Divide (Campbell Pass) in western New Mexico between Gallup and Grants. The last place that I-40 tops 7,000 feet (2,100 m) is at the head of Tijeras Canyon east of Albuquerque at approximately 7,040 feet (2,150 m).
Arizona, New Mexico, Texas, Oklahoma, and Arkansas are the five states where I-40 has a speed limit of 75 mph (121 km/h) instead of the 70 mph (110 km/h) limit in California, Tennessee, and North Carolina.[8][9]
In the westTexas panhandle area, there are several ranch roads connected directly to the Interstate. The only major city in Texas that is directly served by I-40 isAmarillo, which connects withI-27 that runs south towardLubbock. I-40 also connects toUS 287 that runs southeast to Dallas–Fort Worth andUS 87/US 287 north to Dumas and then on into Oklahoma. I-40 has only one welcome center in the state, which is located in Amarillo at the exit forRick Husband Amarillo International Airport, serving both sides of the Interstate.
I-40 goes through the heart of the state, passing through many Oklahoma cities and towns, includingErick,Sayre,Elk City,Clinton,Weatherford,El Reno,Yukon,Oklahoma City,Del City,Midwest City,Shawnee,Okemah,Henryetta,Checotah,Sallisaw, andRoland. I-40 covers 331 miles (533 km) in Oklahoma.
InDowntown Oklahoma City, I-40 was rerouted one mile (1.6 km) south of its former alignment and a 10-lane (five in each direction) facility replaced the formerI-40 Crosstown Bridge; the former I-40 alignment will be replaced with an urban boulevard currently designated as Oklahoma City Boulevard.
I-40 enters the west-central part of the state and runs for 285 miles (459 km) in Arkansas. The route passes throughVan Buren, where it intersects the southboundI-540/US 71 toFort Smith.[10] The route continues east toAlma to intersectI-49 north toFayetteville, Arkansas. Running through theOzark Mountains, I-40 servesOzark,Clarksville,Russellville,Morrilton, andConway. The route turns south after Conway and entersNorth Little Rock, which brings high volume interchanges withI-430,I-30/US 65/US 67/US 167, andI-440/Highway 440 (AR 440).[11] The Interstate continues east throughLonoke,Brinkley, andWest Memphis on the eastside. I-40 briefly overlapsI-55 in West Memphis before it crosses theMississippi River on theHernando de Soto Bridge and entersMemphis, Tennessee.[12]
The State of Tennessee has the longest segment of I-40 at 455 miles (732 km). The Interstate goes through all of the threeGrand Divisions of Tennessee and its three largest cities:Memphis,Nashville, andKnoxville.Jackson,Lebanon,Cookeville,Crossville, andNewport are other notable cities through which I-40 passes. Before leaving the state, I-40 enters theGreat Smoky Mountains towardNorth Carolina.
The section of I-40 which runs between Memphis and Nashville is often referred to as theMusic Highway.[13] During reconstruction, a short section of I-40 through downtown Knoxville near the centralMalfunction Junction was completely closed to traffic from May 1, 2008, and not reopened until June 12, 2009, with all traffic redirected viaI-640, the northern bypass route. The redesigned section now has additional lanes in each direction, is less congested, and has fewer accidents.[14][15]
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InNorth Carolina, I-40 travels 420 miles (680 km). It enters the state as a winding mountain freeway through theGreat Smoky Mountains, which frequently closes due to landslides and weather-related problems. It enters the state on a mostly north–south alignment, turning to a more east–west alignment upon merging withUS 74 at the eastern terminus of theGreat Smoky Mountains Expressway. From there, the highway passes throughAsheville,Hickory, andStatesville before reaching thePiedmont Triad. Just east of the Triad City ofGreensboro, North Carolina, it merges withI-85, and the two roads split again just west of theResearch Triangle area, passing throughDurham andRaleigh. From the Triangle to its eastern terminus inWilmington, it once again takes a more north–south alignment.
A standard distance sign existed near the start of the westbound section of I-40 in Wilmington that indicated the distance to Barstow, California, as 2,554 miles (4,110 km). In 2009, NCDOT said it would not be replaced afterfrequent thefts.[17]
During thecolonial andwestward expansion eras, a number ofNative American trails existed within the vicinity of what is now Interstate 40. In 1857, an expedition led by Lt.Edward Fitzgerald Beale was tasked with establishing a trade route along the35th parallel north fromFort Smith, Arkansas, toLos Angeles. This route, which became known asBeale's Wagon Road, was constructed by a team of about 100 men and 22 camels led by Beale. Completed in 1859, it is generally considered the first federal highway in the Southwestern United States.[18]
In the early 20th century, a number ofauto trails were established by private organizations to aid motorists in traveling between major cities. Among these was theNational Old Trails Road, which roughly followed the western part of present-day I-40 to Albuquerque, and theLee Highway, which followed much of the eastern portion of the route.[19] When the state governments established theUnited States Numbered Highway System in 1926, two of these most important highways,US 66 andUS 70 were established within the present-day I-40 corridor.[20]
US 66, which followed the route from its western terminus to Oklahoma City, became arguably the most famous highway in the United States and has been recognized multiple times in popular culture.[21] US 70, which roughly follows the remainder of the Interstate, was also one of the most important highways for east−west travelers, and was considered part of the "Broadway of America" highway between California andNew York.[22]
An east−west trans-continental freeway to serve the south-central United States was proposed in multiple plans throughout the 1930s and 1940s for what later became theInterstate Highway System.[23] The general alignment for the highway that became I-40 was included in a plan released on August 2, 1947, by the Public Roads Administration of the now-defunctFederal Works Agency.[24] The Interstate was officially authorized between Barstow and Greensboro by theFederal-Aid Highway Act of 1956, which created the Interstate Highway System. The numbering was subsequently approved by theAmerican Association of State Highway Officials (AASHO) on August 14, 1957, along with most of the system.[2]
In 1957, the California Department of Highways, the predecessor agency to theCalifornia Department of Transportation (Caltrans), proposed that the route be renumbered toI-30 instead because of the already existingUS 40 in the state. This route was decommissioned in the state in 1964 as a part of a major revamping of California's overall highway numbering system.[25] The California state government also submittedState Route 58 (SR 58) betweenBarstow andBakersfield for I-40 extension potential in 1956 and 1968, but both of these requests were rejected.[26]
From 1963 to 1966, the US government considered a plan, part ofProject Plowshare, to use atomic bombs to excavate a path for I-40 through California. The project was canceled largely due to the cost of developing the explosives and due to the unavailability of a "clean bomb".[27]
The first sections of I-40 reused freeways that had been constructed prior to the Interstate Highway System or were under construction at the time of the authorization of the system. The first stretch in Tennessee reused a short freeway in Knoxville called the Magnolia Avenue Expressway, which was opened in two segments in 1952 and 1955. The first stretches in North Carolina were a short controlled-access section ofUS 421 in Winston-Salem, and fromKernersville, constructed between 1955 and 1958. By 1957, most states had begun construction on the first sections of I-40.[citation needed] The first construction project specifically for I-40 in 1958 was a section along thePigeon River in Western North Carolina.[28] The stretch between Memphis and Nashville, completed on July 24, 1966, was the first major stretch of interstate highway completed in Tennessee.[29]
On June 30, 1972, the final stretch of I-40 entirely within Arkansas, located betweenClarksville andOzark was opened;[30] the last section to open in the state was theHernando de Soto Bridge, which opened on August 2, 1973.[31][32] The last segment in California to be completed was a short stretch in Needles, opened on August 13, 1973.[33][34] The last original planned stretch of the highway in Tennessee, located east of Knoxville, was partially opened on December 20, 1974,[35] and fully opened on September 12, 1975.[36] The last section of I-40 in Oklahoma, a 17-mile (27 km) stretch nearErick near the western end of the state, opened on June 2, 1975.[37][38]
In 1971, the North Carolina State Highway Commission approved a plan to extend I-40 fromResearch Triangle Park toI-95, a distance of 41 miles (66 km), at a cost of $75 million (equivalent to $443.71 million in 2024[39]). Most of the highway would be four lanes, though six lanes were likely nearRaleigh, where I-40 would extend theBeltline. Several routes were being considered, but, at the time, the most likely route would have ended north ofSmithfield.[40] When the last portion of I-40, connecting Wilmington to Raleigh, was dedicated on June 29, 1990, CBS journalistCharles Kuralt stated:
Thanks to the Interstate Highway System, it is now possible to travel from coast to coast without seeing anything.[41][28]
InMemphis, I-40 was originally planned to pass through the city'sOverton Park, a 342-acre (138 ha) public park. Following a public announcement of the routing, a group of community activists opposed to the routing founded an organization calledCitizens to Preserve Overton Park in 1957, and collected 10,000 signatures in their support.[42] After Secretary of TransportationJohn Volpe authorized the state to solicit bids for the construction of the Interstate through the park in 1969, the organization filed a lawsuit, which culminated in thelandmarkSupreme Court ruling ofCitizens to Preserve Overton Park v. Volpe in 1971, which ruled that the state highway department had not adequately explored alternative routes for the interstate.[43] This case is considered to have established the modern process ofjudicial review of infrastructural projects, and eventually resulted in the state rerouting the alignment of I-40 through the park onto a section of I-240 in 1981.[42][44]
Between May 1980 and March 1982, a major project was conducted on I-40 in Knoxville that widened the route, eliminated several interchanges, added frontage roads, and reconstructed the congestion-prone cloverleaf interchange with I-75, which had earned the nickname "Malfunction Junction", into a three-level stack interchange.[45][46] This was conducted as part of a larger $250 million (equivalent to $686 million in 2024[39]) road improvement project in the Knoxville area in preparation for the1982 World's Fair.[47][48]
Originally, I-40 was constructed through downtownWinston-Salem, and it continued to follow that route until a new urban bypass route was built. After the bypass was completed around 1992, I-40 was relocated to the new freeway, that went through the urban areas of the city while avoiding the congested Downtown. The old highway was then redesignated asInterstate 40 Business (I-40 Bus.), establishing a business route that was actually a freeway for its entire length, a rarity among business routes. Following a reconstruction, the expressway was renamedSalem Parkway and redesignated as part ofUS 421.
The "Big I" interchange in Albuquerque between I-40 and I-25 was reconstructed between 2000 and 2002 in a project that eliminated left-hand entrance ramps and added lanes. This project was given an honorable mention by theUnited States Department of Transportation and the FHWA for excellence in urban highway design in 2002.[49]
TheOklahoma City Crosstown Expressway was relocated and replaced with a new wider alignment in two phases between May 2002 and October 2012. The old alignment was replaced withOklahoma City Boulevard, and at-grade thoroughfare.[50]
In Memphis, the cancellation of the Overton Park stretch of I-240, along with increased traffic volumes and safety hazards, rendered both interchanges with I-240 unable to effectively handle unplanned traffic patterns, thus necessitating their reconstruction. This was accomplished in three phases between January 2001 and December 2016.[51][52][53][54]
A $203.7 million two-phase project dubbed "SmartFix 40" resulted in a complete closure of a short stretch of I-40 through Knoxville between May 1, 2008, and June 12, 2009.[55] This was done in order to accelerate the construction timeline, and during this time, through traffic was required to useI-640.[56] Both phases of the project won an America's Transportation Award from AASHTO in 2008 and 2010, respectively.[57][58]
Landslides are common in the Pigeon River Gorge section along the Tennessee and North Carolina border. Here, the roadway was cut into the slopes of several steep mountains. Accidents on the winding road are also common especially during bad weather. On October 25, 2009, I-40 was closed at the North Carolina and Tennessee border due to a landslide at milemarker 2.6 just east of the Tennessee state line. All traffic was detoured via I-26 and I-81, and non-heavy-load traffic via US 25 and US 70.[59] The roadway was reopened on April 25, 2010, with some remaining limitations on westbound traffic.[60]
On December 23, 1988, atanker truck hauling liquefied propaneoverturned on a ramp in the interchange between I-40 and I-240 in theMidtown neighborhood of Memphis, rupturing a small hole in the front of the tank.[61][62] The leaking gas ignited in a massive fireball, and the tank was propelled 125 yards (114 m) from the crash site into a nearby duplex apartment.[63] The incident killed six motorists and three occupants of nearby structures, and provided momentum for the eventual reconstruction of the interchange.[64][54]
TheI-40 bridge disaster occurred on May 26, 2002, when a barge collided with a bridge foundation member nearWebbers Falls, Oklahoma, causing a 580-foot (180 m) section of the I-40 bridge to plunge into theArkansas River. Automobiles and semitrailers fell into the water, killing 14 people.
On May 11, 2021, theHernando de Soto Bridge carrying I-40 over the Mississippi River was closed when inspectors discovered a crack on a tie girder.[65] A subsequent investigation revealed that the crack had existed since at least May 2019, and reports later surfaced that the crack had likely existed since August 2016.[66][67] An emergency contract to repair the beam was awarded six days after the closure,[68][69] and the bridge reopened on July 31, 2021, to eastbound traffic,[70] and to westbound traffic on August 2, 2021.[71]
The highway was badly damaged duringHurricane Helene in September 2024, with the road closed in multiple locations across western North Carolina due to landslides.[72] The worst damage was seen near North Carolina's border with Tennessee, where a large portion of the highway was washed into thePigeon River following a mudslide, resulting in it being indefinitely closed in both directions.[73][74] On November 5, it was announced that the highway could reopen as early as the beginning of 2025.[75]
I-15 inBarstow
US 95 west-northwest ofNeedles. The highways travel concurrently to Needles.
Future I-11 /US 93 inKingman. The highways travel concurrently to east-northeast of Kingman.
I-17 inFlagstaff
US 89 /US 180 in Flagstaff. I-40/US 180 travels concurrently toHolbrook.
US 191 inChambers. The highways travel concurrently toSanders.
US 491 inGallup
I-25 /US 85 inAlbuquerque
US 285 inClines Corners
US 84 west-northwest ofSanta Rosa. The highways travel concurrently to Santa Rosa.
US 54 in Santa Rosa. The highways travel concurrently toTucumcari.
US 385 inVega
I-27 /US 60 /US 87 /US 287 inAmarillo. I-40/US 287 travels concurrently through Amarillo.
US 83 inShamrock
US 283 inSayre
US 183 inClinton
US 281 inHinton
US 270 west ofEl Reno. The highways travel concurrently to northwest ofShawnee.
US 81 in El Reno
I-44 inOklahoma City
I-35 /I-235 /US 62 /US 77 in Oklahoma City. I-35/I-40/US 62 travels concurrently through Oklahoma City.
I-240 in Oklahoma City
US 177 /US 270 northwest of Shawnee
US 377 south-southeast ofPragueUS 62 inOkemah. The highways travel concurrently toHenryetta.
US 75 northeast ofClearview. The highways travel concurrently to Henryetta.
US 69 southwest ofChecotah
US 266 inWarner
US 59 inSallisaw
US 64 in SallisawUS 64 inRoland
I-540 /US 71 inVan Buren. I-40/US 71 travels concurrently toAlma.
I-49 in AlmaUS 64 inClarksvilleUS 64 inLamarUS 64 inLondon
US 65 inConway. The highways travel concurrently toNorth Little Rock.US 64 in Conway
I-430 in North Little Rock
I-30 /I-57 /US 65 /US 67 /US 167 in North Little Rock. I-40/US 67/US 167 travels concurrently through North Little Rock.
I-440 in North Little Rock
US 63 inHazen. The highways travel concurrently toBrinkley.
US 49 in Brinkley
US 79 south ofJennette. The highways travel concurrently to West Memphis.
I-55 /US 61 /US 64 in West Memphis. The highways travel concurrently through West Memphis.
US 51 inMemphis
I-69 /I-240 in Memphis. I-40/I-69 travels concurrently through Memphis.
US 64 /US 70 /US 79 in MemphisUS 64 on the Memphis–Bartlett city line
I-269 inArlingtonUS 70 east ofBrownsville
US 412 inJackson. The highways travel concurrently to northeast of Jackson.
US 45 in JacksonUS 70 /US 412 northeast of Jackson
US 641 southeast ofHolladay
I-840 southeast ofBurns
US 70S inNashvilleUS 70 in NashvilleI-440 in Nashville
I-65 in Nashville. The highways travel concurrently through Nashville.US 70 in Nashville
US 70 /US 70S /US 431 in Nashville
US 31A /US 41A in Nashville
I-24 in Nashville. The highways travel concurrently through Nashville.I-840 inLebanon
US 231 inLebanonUS 70 in Lebanon
US 70N in CookevilleUS 70N inMonterey
US 127 inCrossville
US 27 inHarriman
US 321 inLenoir City
I-75 west ofFarragut. The highways travel concurrently toKnoxville.
I-140 in Knoxville
US 11 /US 70 in Knoxville
I-75 /I-640 in Knoxville
US 129 in Knoxville
I-275 in Knoxville
US 441 in Knoxville
US 11W in Knoxville
I-640 /US 25W in Knoxville. I-40/US 25W travels concurrently through Knoxville.
US 11E /US 25W /US 70 in KnoxvilleUS 25W /US 70 west ofDandridge
I-81 north-northeast of Dandridge
US 25W /US 70 /US 411 inNewportUS 321 in Newport
US 276 inCove Creek
US 74 north-northwest ofClyde. The highways travel concurrently toAsheville.
US 19 /US 23 in Asheville
I-26 /I-240 /US 74 in Asheville
US 25 in AshevilleI-240 in AshevilleUS 70 inBlack Mountain. The highways travel concurrently to southwest ofOld Fort.
US 221 southeast ofWest MarionUS 64 inMorgantonUS 321 inHickoryUS 64 inStatesville
US 21 in Statesville
I-77 in StatesvilleUS 64 in StatesvilleUS 64 east-northeast of StatesvilleUS 64 west-northwest ofMocksville
US 601 in Mocksville
US 421 inWinston-Salem
US 158 in Winston-Salem
US 52 /I-285 in Winston-Salem
I-74 in Winston-SalemUS 421 west ofGreensboro. The highways travel concurrently to Greensboro.
I-73 /US 421 /I-840 in Greensboro
US 220 in Greensboro. The highways travel concurrently through Greensboro.
US 29 /US 70 in Greensboro. The highways travel concurrently through Greensboro.
I-85 /I-840 /I-785 in Greensboro. I-40/I-85 travels concurrently to southwest ofHillsborough.
US 15 /US 501 inDurham
I-885 in DurhamI-540 in Durham
I-440 /US 1 /US 64 inRaleigh. I-40/US 64 travels concurrently through Raleigh.
US 70 /US 401 in Raleigh
I-87 /I-440 /US 64 in RaleighUS 70 inGarner. The highways travel concurrently to west-southwest ofClayton.
I-42 /US 70 near Clayton.
I-95 inBenson
US 701 south-southeast ofNewton GroveUS 117 south-southeast ofWarsawUS 117 east-southeast ofWillardI-140 inMurraysvilleUS 117 on theKings Grant–Murraysville CDP lineIn Oklahoma City, the designation I-440 had been given to a stretch of Interstate Highway from I-240 to US 66. It was a part of Grand Boulevard that had been built in compliance withInterstate Highway standards. In 1982, as part of Oklahoma's "Diamond Jubilee", I-44's western terminus was moved from the I-35/I-44 junction to the Texas–Oklahoma state line via the Belle Isle Freeway (connecting I-440 with I-35); I-440, the H. E. Bailey Turnpike; and the turnpike connector road on the eastern edge ofLawton, Oklahoma. The I-440 number was dropped at the time.
Geographic data related toInterstate 40 atOpenStreetMap | ||
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