I-540 highlighted in red
|Maintained by ArDOT|
|Length||14.71 mi  (23.67 km)|
|South end||US 271 / AR 253 near Fort Smith|
|North end||I-40 in Van Buren|
Interstate 540 (I-540) is a freeway spur route of I-40 in the US state of Arkansas in Fort Smith. The total length is 14.71 miles (23.67 km).  At first, I-540 was a short spur connecting Fort Smith and Van Buren to I-40 as one of the original five Arkansas Interstates.  The route ran just over 14 miles (23 km) to US 271 near the Oklahoma state line.  The growing Northwest Arkansas area and the University of Arkansas needed an Interstate connection to Little Rock, and through traffic north to Kansas City had also outgrown the winding US 71 north from I-40. The route was extended north to Mountainburg in the late 1990s on an all-new alignment (going under concurrency with I-40, one of the only auxiliary routes with a concurrency with its parent) with the route being completed to Bella Vista in January 1999.  However, the segment north of I-40 became a part of Interstate 49 in 2014.
The older portion of I-540, completed in the 1970s, connects Interstate 40 southwards to the Oklahoma state line, going through Van Buren and Fort Smith. This particular spur starts at Exit 7 on Interstate 40 (being 7 miles (11 km) east of the state line with Oklahoma). That point marks mile zero on this spur, in keeping with Interstate Highway rules that spur mileage begins at the "parent" route. The first 3 miles (5 km) are through Van Buren, before the bridge over the Arkansas River. The remainder, for a grand total of approximately 15 miles (24 km), travels through Fort Smith. AHTD bid a $79 million project in 2013 for I-540 rehabilitation in Fort Smith that includes re-signing the route and renumbering the exits. 
Beginning at the I-540 and I-40 junction in Van Buren, the route begins southward along the eastern boundary of Van Buren, with exits numbered sequentially heading south. The segment is largely concurrent with US 71. The first exit along this segment of I-540/US 71 is with US 64 and US 71B (US 71B), which leads west into the Van Buren Historic District and east to Alma. Continuing south, I-540/US 71 passes over Highway 162 (Kibler Road), with no access between the routes. An exit providing access to Highway 59, via Riggs Drive (southbound) or Twin Circle Drive (northbound), is just prior crossing the Arkansas River. After crossing the river, the highways enter Fort Smith and Sebastian County. I-540/US 71 run through a commercial area and has three exits with city collector roads before an exit for Phoenix Avenue, which gives access to Fort Smith Regional Airport. However, this exit does not have any access to southbound I-540/US 71.
Now turning toward the southwest, I-540/US 71 have exits with Highway 45 (Greenwood Road) and Highway 255 (Zero Street). Following these intersections, US 71 departs I-540 southbound toward Texarkana, with US 71B terminating at the parent route at the exit. I-540 begins to pass through a residential area before its final exit at US 271 and Highway 253. Following this exit, the roadway continues but ceases to be I-540, becoming US 271 and entering Oklahoma.[ citation needed]
The Interstate spur opened in phases. According to a 1970 road map of Fort Smith,[ citation needed] exits 2-11 (Van Buren through the Zero Street exit) were opened, with later exits (12-14) and the roadway itself still under construction. Portions of the roadway that became I-540 around Fayetteville were built in the early 1970s, but upgraded and extended in the mid-1990s. The highway around Fayetteville originally received US 71 signage until the complete I-540 spur was opened.
Originally, I-540 running from I-40 to Oklahoma through Fort Smith was originally signed east–west, but with the construction of the new spur that runs north through Northwest Arkansas to Missouri the entire I-540 was resigned as a north–south road. It is one of the few that have changed this way.[ citation needed]
In the late 1990s, I-540 was extended into Northwest Arkansas. It had been planned since the 1970s as a bypass of U.S. Highway 71. The first section, between Alma and Mountainburg was known as Arkansas Highway 540. Originally, the Arkansas State Highway and Transportation Department (AHTD) asked the American Association of State Highway and Transportation Officials (AASHTO), who are in charge of Interstate and U.S. Highway route numbering, to allow the Interstate segment between Fort Smith and Bentonville to be named I-49, in order to emphasize plans to extend the route from Shreveport, Louisiana, through Arkansas to Kansas City, Missouri.  AASHTO refused and the route opened on January 8, 1999, as a northern extension of I-540.  On October 18, 2013, AASHTO approved AHTD's application to designate I-49 across the state, specifically allowing the state to renumber I-540 as I-49.  The northern section of I-540 was renumbered I-49 in April 2014. 
|Crawford||Van Buren||I-540 ends / I-49 north / I-40 east / US 71 north||Northern end of I-40 Concurrency; Former I-540 north; End I-540|
|14.71||23.67||1||I-40 west ( US 71 north) – Oklahoma City, Little Rock, Fayetteville||Northern end of US 71 concurrency; formerly exit 15; signed as left exit 1A (west) & 1B (east); I-40 exit 7; temporary concurrency with I-49; Southern end of I-40 Concurrency|
|14.20||22.85||2||US 64 ( US 71B) – Van Buren||Signed as exits 2A (west) and 2B (east)|
|11.92||19.18||3||AR 59 – Van Buren|
Crawford- Sebastian County Line
|Sebastian||Fort Smith||5||Kelley Highway|
|8||AR 22 (Rogers Avenue)||Signed as exits 8A (west) and 8B (east) southbound; temporary concurerncy with I-49|
|9||Leigh Avenue / Phoenix Avenue east – Airport||No southbound entrance|
|10||AR 45 (Greenwood Road) / Phoenix Avenue west|
|11||AR 255 (Zero Street)|
|12||US 71 south ( US 71B north) to I-49 – Texarkana||Southern end of US 71 concurrency; temporary concurrency with I-49|
|13||Jenny Lind Road|
|14||US 271 north / AR 253 south||Northern end of US 271 concurrency; I-540 ends|
|||0.00||0.00||US-271 south / SH-9 west – Oklahoma to I-35 – Norman||Oklahoma state line; southern end of US 271 concurrency|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
|Length||12 mi (19 km)|
|Existed||June 7, 1995 –January 8, 1999|
Highway 540 (AR 540, Ark. 540, and Hwy. 540) was a temporary designation for what would later become Interstate 540 between Alma and Mountainburg in the U.S. state of Arkansas. Traveling a distance of approximately 12 miles,[ citation needed] its southern terminus was at I-40 west of Alma and its northern terminus at US 71 in Mountainburg. 
- Planning and Research Division (2010). "Arkansas Road Log Database". Arkansas State Highway and Transportation Department. Archived from the original (Database) on June 23, 2011. Retrieved June 9, 2011.
- Arkansas State Highway and Transportation Department (1992). "The Beginning of the Mack-Blackwell Years". Historical Review: Arkansas State Highway Commission and Arkansas State Highway and Transportation Department, 1913–1992. Little Rock: Arkansas State Highway and Transportation Department. p. 89.
- Arkansas State Highway and Transportation Department (1988). Highway Map of Arkansas (TIFF) (Map). Little Rock: Arkansas State Highway and Transportation Department. Retrieved March 20, 2012.
- Arkansas State Highway and Transportation Department (2004). "The 90s". Historical Review Volume Two: Arkansas State Highway Commission and Arkansas State Highway and Transportation Department, 1913–2003. Little Rock: Arkansas State Highway and Transportation Department.
- Mitchell, Aric (January 7, 2013). "I-540 in Fort Smith, Van Buren Set for $78 Million Rehab". The City Wire. Retrieved December 24, 2013.
- Arkansas State Highway Commission (January 22, 1991). "Minutes of the Meeting" (PDF). Arkansas State Highway Commission. p. 868. Retrieved December 24, 2013.
- Arkansas State Highway Commission (August 6, 1997). "Minutes of the Meeting" (PDF). Arkansas State Highway Commission. p. 960. Retrieved December 24, 2013.
- Special Committee on U.S. Route Numbering (October 28, 2013). "Special Committee on US Route Numbering Meeting Minutes for October 17, 2013 and Report to SCOH October 18, 2013" (PDF) (Report). Washington, DC: American Association of State Highway and Transportation Officials. p. 2. Retrieved May 4, 2014.
- Rozelle, Jonathan. "I-540 Becomes Interstate 49". Fort Smith–Rogers, AR: KHBS/KHOG-TV. Retrieved May 4, 2014.
- Arkansas State Highway Commission (June 7, 1995). "Minutes of the Meeting" (PDF). Arkansas State Highway Commission. pp. 647–648. Retrieved December 24, 2013.
- Media related to Interstate 540 at Wikimedia Commons