|Length:||2,555.10 mi (4,112.03 km)|
|West end:||I-15 in Barstow, California|
| I-25 in Albuquerque, NM
I-35 in Oklahoma City, OK
I-30 in North Little Rock, AR
I-55 in West Memphis, AR
I-65 in Nashville, TN
I-24 in Nashville, TN
I-75 in Knoxville, TN
I-85 in Greensboro, NC
I-95 in Benson, NC
|East end:||US 117 / NC 132 in Wilmington, North Carolina|
Interstate 40 (I-40) is the third-longest major east–west Interstate Highway in the United States, after I-90 and I-80. Its western end is at Interstate 15 in Barstow, California; its eastern end is at a concurrency of U.S. Route 117 and North Carolina Highway 132 in Wilmington, North Carolina. Much of the western part of I-40, from Oklahoma City to Barstow, parallels or overlays the historic U.S. Route 66. I-40 intersects with eight of the 10 primary north–south interstates (all except I-5 and I-45) and also with I-24, I-30, I-44, I-77, and I-81.
Route description 
Interstate 40 is a major east–west route of the Interstate Highway System. Its western end is in Barstow, California, United States. 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.
Interstate 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 miles (578 km) in Arizona. Just west of exit 190, west of Flagstaff, is highest elevation along I-40 in the US, as the road crosses just over 7,320 feet.
New Mexico 
I-40 covers 374 miles (602 km) in New Mexico. Notable cities along I-40 include Albuquerque, Santa Rosa, Tucumari, Grants and Gallup. I-40 also travels through several different Indian reservations in the western half of the state. Arizona, New Mexico, and Texas are the only three states where I-40 has a speed limit of 75 mph (120 km/h) instead of 70 mph (112 km/h).
In the west Texas panhandle area, there are several ranch roads connected directly to the interstate. One of the marked at-grade crossings is shown to the right. The only major city in Texas that is directly served by I-40 is Amarillo, which connects with Interstate 27 that runs south toward Lubbock. Due to the small amount of territory covered by I-40, only one Texas welcome center is located along this stretch of road, in Amarillo at the exit for Rick Husband Amarillo International Airport, serving both sides of the interstate.
Interstate 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, Midwest City, Shawnee, Okemah, Henryetta, Checotah, Sallisaw, and Roland. I-40 covers 331 miles (533 km) in Oklahoma. In downtown Oklahoma City An ongoing project is underway. It will feature 10 lanes (5 in each direction) and allow for the dismantling of the crosstown bridge, which will in turn be replaced by a landscaped boulevard. Motorists should check ahead for construction updates on ODOT's website as there are frequently lane closures which result in traffic backups on this section, especially at night but also at rush hour since if there is an accident or someone breaks down, there is no place for them to pull off.
Interstate 40 enters the west-central part of the state and runs for 284 miles (457 km) in Arkansas. The route passes through Van Buren, where it intersects the southbound Interstate 540/US 71 to Fort Smith. The route continues east to Alma to intersect I-540 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 Interstate 430, I-30/US 65/US 67/US 167, and Interstate 440/AR 440. The interstate continues east through Lonoke, Brinkley, and West Memphis on the eastern side. Interstate 40 briefly overlaps Interstate 55 in West Memphis before it crosses the Mississippi River on the Hernando de Soto Bridge and enters Memphis, Tennessee.
More of Interstate 40 passes through Tennessee, 455 miles (732 km), than any other state. 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 and/or towns through which I-40 passes. Before leaving the state, I-40 enters the Great Smoky Mountains.
The section of Interstate 40 which runs between Memphis and Nashville is often referred to as the Music Highway During reconstruction, a long 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 Interstate 640, the northern bypass route. The redesigned section now has additional lanes in each direction, is less congested, and has fewer accidents.
North Carolina 
In North Carolina, I-40 merges with I-85 between Greensboro and Hillsborough, just west of Durham. In Alamance County, the highway is also known as the Sam Hunt Freeway. Due to a recent rerouting of I-85 around Greensboro, I-40 departs from it eight miles (13 km) east of the original split. From February to Mid September 2008 I-40 was moved to a new alignment south of Greensboro, which also carries the new I-85 bypass and will eventually carry Interstate 73 as well, while the old I-40 through Greensboro became a second I-40 freeway Business Loop. However, on September 12, 2008 after complaints from motorists and residents, NCDOT got permission from the FHWA to put I-40 back onto the old alignment through Greensboro. This resulted in the decommissioning of Interstate 40 Business through Greensboro. This was also done to maintain federal funding on the old I-40 route. To make up for the removal of I-40 from the loop, US 421 was rerouted onto I-40's previous alignment. I-40 covers 421 miles (678 km) in North Carolina.
In violation of Interstate standards, I-40 has one marked and two unmarked at-grade crossings in western North Carolina. About eight miles (13 km) from the Tennessee state-line in North Carolina, when going westwards, a sign for "Hurricane Creek Road" appears. Hurricane Creek Road is a local dirt road whose quality is below that of the shoulder, and the intersection is controlled by a stop sign. It is a right-in, right-out entrance. Two other unmarked local roads directly link onto I-40 in the area, including a private access road for Walters Dam between mile markers 11 and 12 on the westbound side.
A standard distance sign exists near the start of the westbound section of I-40 in Wilmington that indicates the distance to Barstow, California as 2,554 miles (4,110 km). Although NCDOT has stated it wouldn't be replaced after frequent thefts, as of May 7, 2012, the sign is present.
For about 1,000 miles (1,600 km), I-40 follows the general route of the Beale Wagon Road from Arkansas to California. The Beale 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. 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. Rte-40 was decommissioned in California in 1964, as a part of a major revamping of California's overall highway numbering system, so the problem disappeared.
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. This portion of SR 58 was once signed as the U.S. Route 466.
From 1963 to 1966, the US government considered a plan, part of Operation Plowshare, to use atomic bombs to excavate a path for I-40 through California. The project was scuttled largely due to the cost of developing the explosives and due to the unavailability of a "clean bomb".
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, 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 Interstate 240 loop was redesignated as I-40.
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.
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.||”|
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, creating a business route that is actually an expressway for its entire length, a rarity among business routes. There are arguments that the former I-40 expressway in Winston-Salem should become an interstate again, especially since the road is currently undergoing an upgrade. There are no even loop numbers left for I-40, however, since the NCDOT has plans to use last available one Interstate 840 for the northern loop of a beltway that is being built around nearby Greensboro.
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.
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 25/70. The roadway was reopened on April 25, 2010 with some remaining limitations on westbound traffic.
Major intersections 
- Interstate 15 in Barstow, California
- Interstate 17 in Flagstaff, Arizona
- Interstate 25 in Albuquerque, New Mexico
- Interstate 27 in Amarillo, Texas
- Interstate 35 in Oklahoma City, Oklahoma
- Interstate 44 in Oklahoma City, Oklahoma
- Future Interstate 49 outside Fort Smith, Arkansas (partially built and in service as Interstate 540).
- Interstate 30 in North Little Rock, Arkansas
- Interstate 55 in West Memphis, Arkansas (the freeways are merged throughout this town)
- Proposed Interstate 69 in Memphis, Tennessee
- Interstate 24 in Nashville, Tennessee merged for approximately 2 miles (3.2 km)
- Interstate 65 in Nashville, Tennessee merged for approximately 3 miles (4.8 km)
- Interstate 75 near Dixie Lee Junction, Tennessee. They stay merged until Knoxville, Tennessee.
- Interstate 81 near Dandridge, Tennessee
- Interstate 26 in Asheville, North Carolina
- Interstate 77 in Statesville, North Carolina
- Future Interstate 74 in Winston-Salem, North Carolina
- Future Interstate 73 in Greensboro, North Carolina
- Interstate 85 in Greensboro, North Carolina. They stay merged until Hillsborough, North Carolina.
- Interstate 95 in Benson, North Carolina (Map)
Auxiliary routes 
- I-140 - Alcoa - Knoxville - Oak Ridge area
- I-140 - Wilmington, North Carolina
- I-240 - Asheville, North Carolina
- I-240 - Memphis, Tennessee
- I-240 - Oklahoma City, Oklahoma
- I-440 - Little Rock, Arkansas
- I-440 - Nashville, Tennessee
- I-440 - Raleigh, North Carolina
- I-540 - Spurs to Fort Smith, Arkansas, and the Northwest Arkansas metro area. It is proposed to become part of an extended Interstate 49
- I-540 - Raleigh, North Carolina
- I-640 - Knoxville, Tennessee
- I-840 - Greensboro, North Carolina
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 compliace with Interstate 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, but it might return again sometime in the future.
See also 
Business routes 
- Interstate 40 Business in Raleigh, North Carolina, now Interstate 440
- Interstate 40 Business (North Carolina) in Winston-Salem, North Carolina and formerly in Greensboro, too
- Interstate 40 Business in Oklahoma - Sallisaw; Henryetta; El Reno; Weatherford; Clinton; Elk City; Sayre; and Erick, Oklahoma
- Interstate 40 Business in Texas - Shamrock; McLean; Groom; Amarillo; Vega; Adrian, Texas; and Glenrio, New Mexico and Texas
- Interstate 40 Business in New Mexico - Tucumcari; Santa Rosa; Albuquerque; Grants, Mount Taylor, and Gallup, New Mexico
- Interstate 40 Business in Arizona — Spur to Winslow; Loops through Winslow; Flagstaff; Williams; Ash Fork; Seligman; and Kingman, Arizona
- Interstate 40 Business in California - Needles, California
- "Route Log - Main Routes of the Eisenhower National System Of Interstate and Defense Highways - Table 1". Fhwa.dot.gov. 2002-10-31. Retrieved 2011-11-27.
- "I-40 Barstow, Calif., sign gone for good". StarNewsOnline.com. 2009-11-12. Retrieved 2011-09-19.
- Arkansas State Highway and Transportation Department (2011) (PDF). General Highway Map, Crawford County, Arkansas (Map). 1:62500. Cartography by Planning and Research Division. http://www.arkansashighways.com/maps/Counties/County%20PDFs/CrawfordCounty.pdf. Retrieved November 15, 2011.
- Arkansas State Highway and Transportation Department (2009) (PDF). General Highway Map, Pulaski County, Arkansas (Map). 1:62500. Cartography by Planning and Research Division. http://www.arkansashighways.com/maps/Counties/County%20PDFs/PulaskiCounty.pdf. Retrieved November 15, 2011.
- Arkansas State Highway and Transportation Department (2009) (PDF). General Highway Map, Crittenden County, Arkansas (Map). 1:62500. Cartography by Planning and Research Division. http://www.arkansashighways.com/maps/Counties/County%20PDFs/CrittendenCounty.pdf. Retrieved November 15, 2011.
- Tennessee public acts 2001 Chapter 100, Senate Bill 916 House Bill 616 Signed into law 18 April 2001 http://www.tennessee.gov/sos/acts/102/pub/pc0100.pdf
- SmartFix - I-40/James White Parkway/Hall of Fame Drive - Tennessee Department of Transportation[dead link]
- SmartFix - I-40/James White Parkway/Hall of Fame Drive - Tennessee Department of Transportation[dead link]
- Posted by Adam (2008-04-06). "Sure, Why Not? - Street Signs on an Interstate? No way!". Surewhynotnow.blogspot.com. Retrieved 2011-11-27.
- "California Highways: Interstate 40". Cahighways.org. Retrieved 2011-11-27.
- Waller, Jeff. Interstate 40 Extension and Bakersfield Freeway Network. California Streets. URL accessed 21:19, 18 February 2006 (UTC).
- Wilshire, Howard (Spring 2001). "Building a Radioactive Highway" (PDF). Desert Report (Sierra Club). pp. 9, 14.[dead link]
- "SHC Approves I-40 Link in Wake County," Concord Tribune (Associated Press), July 20, 1971.
- Wilson, Amy. U.S. Route 66: Historic Road Is Time Line of America. National Geographic News. January 18, 2002. URL accessed 21:31, 18 February 2006 (UTC).
- "Excellence in Highway Design - 2002 I-25/I-40 System-to-System Interchange, Albuquerque, New Mexico". Fhwa.dot.gov. Retrieved 2011-11-27.
- "HWY 25-70 a scenic, tough rock slide detour". Volunteertv.com. Retrieved 2011-11-27.
- Hickman, Hayes (2010-04-26). "Section of I-40 closed since Oct. rockslide reopens". Knoxville News Sentinel. Retrieved 2010-04-26.
|Wikimedia Commons has media related to: Interstate 40|
- Geographic data related to Interstate 40 at OpenStreetMap
- Interstate-Guide: I-40
- The Beale Wagon Road
- The I-40 Bridge Disaster[dead link]
- WestCoastRoads - Interstate 40
- California Highways: I-40
- Cal-NExUS: Route 40 West[dead link]
- Cal-NExUS: Route 40 East[dead link]