Interstate 40

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Interstate 40 marker
Interstate 40
Route information
Length2,556.61 mi[1] (4,114.46 km)
Major junctions
West end I-15 in Barstow, CA
East end US 117 in Wilmington, NC
StatesCalifornia, Arizona, New Mexico, Texas, Oklahoma, Arkansas, Tennessee, North Carolina
Highway system

Interstate 40 (I-40) is a major east–west Interstate Highway running through the south-central portion of the United States generally north of I-10, I-20 and I-30 but south of I-70. The western end is at I-15 in Barstow, California; its eastern end is at a concurrency of U.S. Route 117 (US 117) and North Carolina Highway 132 in Wilmington, North Carolina. I-40 is the third-longest Interstate Highway in the United States, behind I-80 and I-90. Much of the western part of I-40, from Barstow to Oklahoma City, parallels or overlays the historic US 66; east of Oklahoma City the route generally parallels US 64 and US 70. I-40 runs through or near many major cities including Albuquerque, New Mexico; Amarillo, Texas; Oklahoma City, Oklahoma; Little Rock, Arkansas; Memphis, Tennessee; Nashville, Tennessee; Knoxville, Tennessee; Greensboro, North Carolina; and Raleigh, North Carolina.

Route description[edit]

I-40 runs east–west through eight states. The state with the longest segment of the highway is Tennessee; the shortest state segment is in California.

  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


A sign at the start of I-40 in Barstow, California showing the distance to the freeway's eastern terminus in Wilmington, North Carolina. This sign has been stolen several times.

I-40 in California crosses through the lightly-populated western part of the Inland Empire region of the state. Its western end is in Barstow, California. Known as the Needles Freeway, it heads east from Barstow across the Mojave Desert in San Bernardino County to Needles, before it crosses into Arizona southwest of Kingman. I-40 covers 155 miles (249 km) in California. Some signs show the control city for I-40 westbound to be Los Angeles, where drivers would follow I-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 to Wilmington, North Carolina, has been stolen several times.[3]


I-40 westbound heading towards Flagstaff

I-40 is a main route to the South Rim of the Grand Canyon, with the exits leading into Grand Canyon National Park in Williams and Flagstaff. I-40 covers 359 mi (578 km) in Arizona. Just west of exit 190, west of Flagstaff, is its highest elevation along I-40 in the U.S., as the road crosses just over 7,320 feet (2,230 m). I-40 also passes through the Navajo Nation, the largest Indian reservation in the U.S. Like California's segment, the highway is four lanes for the entirety of its length in the state.

New Mexico[edit]

I-40 covers 374 miles (602 km) in New Mexico. Notable cities along I-40 include Gallup, Grants, Albuquerque, Santa Rosa, and Tucumcari. I-40 also travels through several different Indian 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 in western New Mexico between Gallup and Grants.

Arizona, New Mexico, Texas, Oklahoma,[4] and Arkansas[5] are the five states where I-40 has a speed limit of 75 miles per hour (121 km/h) instead of the 70 miles per hour (110 km/h) limit in California, Tennessee, and North Carolina.


An at-grade intersection on I-40 in Texas in 2003

In the west Texas 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 is Amarillo, which connects with I-27 that runs south toward Lubbock. I-40 also connects to US 287 that runs south to Dallas–Fort Worth and US 87/287 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 for Rick 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, including Erick, Sayre, Elk City, Clinton, Weatherford, El Reno, Yukon, Oklahoma City, Del City, Midwest City, Shawnee, Okemah, Henryetta, Checotah, Sallisaw, and Roland. I-40 covers 331 miles (533 km) in Oklahoma.

In Downtown Oklahoma City, I-40 was rerouted a mile south of its former alignment and a 10-lane (five in each direction) facility replaced the former I-40 Crosstown Bridge; itself will be replaced with an urban boulevard currently designated as Oklahoma City Boulevard.[clarification needed]


The Hernando de Soto Bridge, where I-40 crosses the Mississippi River into Memphis

I-40 enters the west-central part of the state and runs for 285 miles (459 km) in Arkansas. The route passes through Van Buren, where it intersects the southbound I-540/US 71 to Fort Smith.[6] The route continues east to Alma to intersect Interstate 49 north to Fayetteville, Arkansas. Running through the Ozark Mountains, I-40 serves Ozark, Clarksville, Russellville, Morrilton and Conway. The route turns south after Conway and enters North Little Rock, which brings high volume interchanges with I-430, I-30/US 65/US 67/US 167, and I-440/AR 440.[7] The interstate continues east through Lonoke, Brinkley, and West Memphis on the eastern side. I-40 briefly overlaps I-55 in West Memphis before it crosses the Mississippi River on the Hernando de Soto Bridge and enters Memphis, Tennessee.[8]


The state of Tennessee has the longest segment of I-40 at 455 miles (732 km). The Interstate goes through all of the three Grand Divisions of Tennessee and its three largest cities, Memphis, Nashville and Knoxville. Jackson, Lebanon, Cookeville, Crossville, and Newport are other notable cities through which I-40 passes. Before leaving the state, I-40 enters the Great Smoky Mountains towards North Carolina.

The section of I-40 which runs between Memphis and Nashville is often referred to as the Music Highway.[9] During reconstruction, a short section of I-40 through downtown Knoxville near the central Malfunction Junction was completely closed to traffic from May 1, 2008, and not reopened until June 12, 2009, with all traffic redirected via I-640, the northern bypass route. The redesigned section now has additional lanes in each direction, is less congested, and has fewer accidents.[10][11]

North Carolina[edit]

Sign displaying distance to Barstow in Wilmington. This sign is no longer posted by NCDOT due to the frequency of its theft.[12]
Beginning of I-40 west, Wilmington

In North Carolina, I-40 travels 420 miles (680 km). It enters the state as a winding mountain freeway through the Great Smoky Mountains which frequently closes due to landslides and weather conditions. It enters the state on a mostly north–south alignment, turning to a more east–west alignment upon merging with US 74 at the eastern terminus of the Great Smoky Mountains Expressway. From there the highway passes through Asheville, Hickory, and Statesville before reaching the Piedmont Triad. Just east of the Triad city of Greensboro, North Carolina it merges with I-85 and the two roads split again just west of the Research Triangle area, passing through Durham and Raleigh. From the Triangle to its eastern terminus in Wilmington, 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). Although NCDOT stated[when?] it would not be replaced after frequent thefts, as of August 15, 2013, the sign was still present. However, between 2013 and 2020, the sign and base were removed, replaced by a sign proclaiming the stretch as the Michael Jordan Freeway.


For about 1,000 miles (1,600 km), I-40 follows the general route of Beale's Wagon Road from Arkansas to California. Beale's Wagon Road was built in 1857–59 by a team led by Lt. Edward Fitzgerald Beale using a team of camels as pack animals.

In Albuquerque, New Mexico, I-40 was originally meant to replace Central Avenue through the center of the city. However, due to development and public opposition, a route running to the north of that one was chosen.[citation needed] The freeway intersects Central Ave. at both ends of the city.

In 1957, the California Department of Highways proposed that the route be renumbered to Interstate 30 instead, because of the already existing U.S. Route 40 in the state. Then, U.S. Route 40 was decommissioned in California in 1964, as a part of a major revamping of California's overall highway numbering system, so the problem was resolved.[13][self-published source]

The California State government submitted State Route 58 between Barstow and Bakersfield for I-40 extension potential in 1956 and 1968, though those requests were rejected.[14][self-published source] This portion of SR 58 was once signed as the U.S. Route 466.

From 1963 to 1966, the U.S. government considered a plan, part of Project Plowshare, to use atomic bombs to excavate a path for I-40 through California. The project was cancelled largely due to the cost of developing the explosives and due to the unavailability of a "clean bomb".[15]

In Memphis, I-40 was originally intended to go through the city's Overton Park toward downtown. Several miles of interstate were actually built within the I-240 loop. That portion of highway still exists,[timeframe?] and it is in regular use as the non-Interstate Sam Cooper Boulevard, reaching the eastern end of the Chickasaw Country Club. Environmentalist opposition, combined with a victory in the United States Supreme Court by opponents of the Overton Park route (see Citizens to Preserve Overton Park v. Volpe) forced abandonment of the original plans, and the road never reached the park. For over 20 years, I-40 signs existed on the dead-end route toward Overton Park. Eventually, the northern span of the I-240 loop was redesignated as I-40.[citation needed]

In 1971, the North Carolina State Highway Commission approved a plan to extend I-40 from Research Triangle Park to Interstate 95, a distance of 41 miles, at a cost of $75 million. Most of the highway would be four lanes, though six lanes were likely near Raleigh, where I-40 would extend the Beltline. Several routes were being considered, but at the time, the most likely route would have ended north of Smithfield.[16]

When the last portion of I-40, connecting Wilmington to Raleigh, was completed in the late 1980s, Charles Kuralt stated:

Thanks to the interstate highway system, it is now possible to travel from coast to coast without seeing anything.[17]

Originally, I-40 was constructed through downtown Winston-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. The old highway was then redesignated as Interstate 40 Business, establishing a business route that was actually an expressway for its entire length, a rarity among business routes. Following a reconstruction, the expressway was renamed Salem Parkway and redesignated as part of US 421.

The collapsed section of the I-40 bridge, May 31, 2002

The I-40 bridge disaster occurred on May 26, 2002, when a barge collided with a bridge foundation member near Webbers Falls, Oklahoma, causing a 580-foot (177 m) section of the I-40 bridge to plunge into the Arkansas River. Automobiles and semi-trailers fell into the water, killing fourteen people.

The "Big I" I-25 and I-40 interchange in Albuquerque, New Mexico, was given an honorable mention by the United States Department of Transportation and the Federal Highway Administration for excellence in urban highway design in 2002.[18]

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, Interstate 40 was closed at the North Carolina and Tennessee border due to a landslide at Mile Marker 2.6 just east of the Tennessee state line. All traffic was detoured via Interstates 26 and 81, and non-heavy load traffic via US routes 25 and 70.[19] The roadway was reopened on April 25, 2010, with some remaining limitations on westbound traffic.[20]

On May 11, 2021, the Hernando de Soto Bridge carrying I-40 over the Mississippi River was closed following the discovery of a split in one of the bridge members.[21]

Major junctions[edit]

I-15 in Barstow
US 95 west-northwest of Needles. The highways travel concurrently to Needles.
Future I-11 / US 93 in Kingman. The highways travel concurrently to east-northeast of Kingman.
I-17 in Flagstaff
US 89 / US 180 in Flagstaff. I-40/US 180 travels concurrently to Holbrook.
US 191 in Chambers. The highways travel concurrently to Sanders.
New Mexico
US 491 in Gallup
I-25 / US 85 in Albuquerque
US 285 in Clines Corners
US 84 west-northwest of Santa Rosa. The highways travel concurrently to Santa Rosa.
US 54 in Santa Rosa. The highways travel concurrently to Tucumcari.
US 385 in Vega
I-27 / US 60 / US 87 / US 287 in Amarillo. I-40/US 287 travels concurrently through Amarillo.
US 83 in Shamrock
US 283 in Sayre
US 183 in Clinton
US 281 in Hinton
US 270 west of El Reno. The highways travel concurrently to northwest of Shawnee.
US 81 in El Reno
I-44 in Oklahoma 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 of Prague
US 62 in Okemah. The highways travel concurrently to Henryetta.
US 75 northeast of Clearview. The highways travel concurrently to Henryetta.
US 69 southwest of Checotah
US 266 in Warner
US 59 in Sallisaw
US 64 in Sallisaw
US 64 in Roland
I-540 / US 71 in Van Buren. I-40/US 71 travels concurrently to Alma.
I-49 in Alma
US 64 in Clarksville
US 64 in Lamar
US 64 in London
US 65 in Conway. The highways travel concurrently to North Little Rock.
US 64 in Conway
I-430 in North Little Rock
I-30 / Future 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 in Hazen. The highways travel concurrently to West Memphis.
US 49 in Brinkley
US 79 south of Jennette. The highways travel concurrently to West Memphis.
I-55 / US 61 / US 63 / US 64 in West Memphis. I-40/I-55/US 61/US 64 travels concurrently through West Memphis.
US 51 in Memphis
I-69 / I-240 in Memphis. I-40/I-69 travels concurrently through Memphis.
US 64 / US 70 / US 79 in Memphis
I-240 in Memphis
US 64 on the Memphis–Bartlett city line
US 70 east of Brownsville
US 412 in Jackson. The highways travel concurrently to northeast of Jackson.
US 45 in Jackson
US 70 / US 412 northeast of Jackson
US 641 southeast of Holladay
US 70S in Nashville
US 70 in Nashville
I-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
I-24 in Nashville. The highways travel concurrently through Nashville.
US 231 in Lebanon
US 70 in Lebanon
US 70N in Cookeville
US 70N in Monterey
US 127 in Crossville
US 27 in Harriman
US 321 in Lenoir City
I-75 west of Farragut. The highways travel concurrently to Knoxville.
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 Knoxville
US 25W / US 70 west of Dandridge
I-81 north-northeast of Dandridge
US 25W / US 70 / US 411 in Newport
US 321 in Newport
North Carolina
US 276 in Cove Creek
US 74 north-northwest of Clyde. The highways travel concurrently to Asheville.
US 19 / US 23 in Asheville
I-26 / I-240 / US 74 in Asheville
US 25 in Asheville
I-240 in Asheville
US 70 in Black Mountain. The highways travel concurrently to southwest of Old Fort.
US 221 southeast of West Marion
US 64 in Morganton
US 321 in Hickory
US 64 in Statesville
US 21 in Statesville
I-77 in Statesville
US 64 in Statesville
US 64 east-northeast of Statesville
US 64 west-northwest of Mocksville
US 601 in Mocksville
US 421 in Winston-Salem
US 158 in Winston-Salem
US 52 in Winston-Salem
I-74 in Winston-Salem
US 421 west of Greensboro. The highways travel concurrently to Greensboro.
I-73 / US 421 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 in Greensboro. The highways travel concurrently to southwest of Hillsborough.
US 15 / US 501 in Durham
I-540 in Durham
I-440 / US 1 / US 64 in Raleigh. I-40/US 64 travels concurrently through Raleigh.
US 70 / US 401 in Raleigh
I-87 / I-440 / US 64 in Raleigh
US 70 in Garner. The highways travel concurrently to west-southwest of Clayton.
Future plate blue.svg No image wide.svg
Future I-42 / US 70 near Clayton.
I-95 in Benson
US 701 south-southeast of Newton Grove
US 117 south-southeast of Warsaw
US 117 east-southeast of Willard
I-140 in Murraysville
US 117 on the Kings Grant–Murraysville CDP line

Auxiliary routes[edit]

In 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 with Interstate 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 of Lawton, Oklahoma. The I-440 number was dropped at the time.

Business routes[edit]

In popular culture[edit]

I-40 plays a major role in the 2006 Disney/Pixar animated film Cars. The film takes place in the fictional town of Radiator Springs located along U.S. Route 66 and tells about how Radiator Springs was once a popular stop along U.S. Route 66 until it was bypassed by I-40 and was mostly forgotten.

See also[edit]


  1. ^ a b Adderly, Kevin (January 27, 2016). "Table 1: Main Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways as of December 31, 2015". Federal Highway Administration. Retrieved February 8, 2017.
  2. ^ American Association of State Highway Officials (August 14, 1957). Official Route Numbering for the National System of Interstate and Defense Highways (Map). Scale not given. Washington, DC: American Association of State Highway Officials. Retrieved March 27, 2017 – via Wikimedia Commons.
  3. ^ "I-40 Barstow, Calif., sign gone for good". November 12, 2009. Retrieved October 20, 2020.
  4. ^ "Speed limit on much of I-40, I-35 raised to 75 MPH".
  5. ^ "Speed limit on I-40 in the River Valley increases to 75 MPH".
  6. ^ Planning and Research Division (2011). General Highway Map, Crawford County, Arkansas (PDF) (Map). 1:62,500. Little Rock: Arkansas State Highway and Transportation Department. Retrieved November 15, 2011.
  7. ^ Planning and Research Division (2009). General Highway Map, Pulaski County, Arkansas (PDF) (Map). 1:62,500. Little Rock: Arkansas State Highway and Transportation Department. Retrieved November 15, 2011.
  8. ^ Planning and Research Division (2009). General Highway Map, Crittenden County, Arkansas (PDF) (Map). 1:62,500. Little Rock: Arkansas State Highway and Transportation Department. Retrieved November 15, 2011.
  9. ^ Tennessee public acts 2001 Chapter 100, Senate Bill 916 House Bill 616 Signed into law April 18, 2001,
  10. ^ Tennessee Department of Transportation. "SmartFix: I-40/James White Parkway/Hall of Fame Drive". Tennessee Department of Transportation. Archived from the original on December 31, 2010.
  11. ^ Tennessee Department of Transportation. "SmartFix: I-40/James White Parkway/Hall of Fame Drive". Tennessee Department of Transportation. Archived from the original on April 29, 2009.
  12. ^ Star News, Staff Reports. "I-40 Barstow, Calif., sign gone for good". Star News Online. Star News. Retrieved October 15, 2020.
  13. ^ "Interstate 40". California Highways. Retrieved November 27, 2011.[self-published source]
  14. ^ Waller, Jeff. "Interstate 40 Extension and Bakersfield Freeway Network". California Streets. Retrieved February 18, 2006.[self-published source]
  15. ^ Wilshire, Howard (Spring 2001). "Building a Radioactive Highway" (PDF). Desert Report. Sierra Club. pp. 9, 14. Archived from the original (PDF) on March 26, 2009.
  16. ^ "SHC Approves I-40 Link in Wake County". Concord Tribune. Associated Press. July 20, 1971.
  17. ^ Wilson, Amy (January 18, 2002). "U.S. Route 66: Historic Road Is Time Line of America". National Geographic News. Retrieved February 18, 2006.
  18. ^ "Excellence in Highway Design - 2002 I-25/I-40 System-to-System Interchange, Albuquerque, New Mexico". Federal Highway Administration. Retrieved November 27, 2011.
  19. ^ "HWY 25-70 a scenic, tough rock slide detour". Retrieved November 27, 2011.
  20. ^ Hickman, Hayes (April 26, 2010). "Section of I-40 closed since Oct. rockslide reopens". Knoxville News Sentinel. Retrieved April 26, 2010.
  21. ^ "Urgent 911 calls after major crack found in Interstate 40 bridge linking Arkansas and Tennessee". CBS News. May 15, 2021. Retrieved May 17, 2021.

External links[edit]

Route map:

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