I-440 highlighted in red
|Maintained by TDOT|
|Length||7.64 mi  (12.30 km)|
|West end||I-40 in Nashville|
|I-65 in Nashville|
|East end||I-24 / I-40 in Nashville|
Interstate 440 (I-440) is a 7.64-mile-long (12.30 km) auxiliary loop interstate highway in Davidson County, Tennessee which serves as a southern bypass for downtown Nashville. The route is known locally as the Four-Forty Parkway and connects to I-40, I-65, and I-24, as well as multiple U.S. and state routes.
The majority of I-440 is located below the street level of adjoining streets and roads, in an artificially-cut gulch. It has three lanes in each direction, separated by a narrow grassy median, which makes it susceptible to crossover crashes.  Most of the route is also landscaped, and shares engineering similarities to that of a parkway, such as curbed inner edges. The entire route is made of concrete. 
West of downtown Nashville, I-440 heads south from I-40 and goes on to meet U.S. Route 70S (US 70S) before turning due east. I-440 then has an interchange with US 431. Then, it has an interchange with I-65 south of downtown Nashville in a symmetrical " Spaghetti Junction" stack interchange, which includes four flyover ramps. I-440 then turns northeast and meets US 31A/ US 41A before terminating at I-24, west of the Nashville International Airport. I-40 eastbound is also directly accessible from this interchange, as is westbound I-440 from I-40 westbound. 
The route that is now Interstate 440 had its origins in 1955, when the interstate highway system was being planned. After the Interstate Highway Act was passed, a public meeting was held in 1957 that identified proposed interstate highways and bypass routes around the city, and I-440 was initially known as "State Route 516." 
The project experienced many setbacks, and was subject to much controversy.  TDOT was authorized to make right-of-way acquisitions for the first section, located between I-40 and I-65 in 1961 and the next section, between I-65 and I-24, in 1968.  Around that time a lawsuit was filed against the department, alleging that they had purchased right-of-way for an unplanned interchange. TDOT won the lawsuit after they showed that the project was in the public interest. 
The construction of the parkway required the demolition of many homes, and many Nashville residents opposed the project. Throughout the 1970s many groups campaigned to stop the construction of the highway. But traffic studies determined that the highway was necessary to relieve congestion on I-40.  In 1981 a group of community activists known as the "Nashvillians Against I-440" filed Nashvillians Against I-440 v. Lewis in a U.S. District Court hoping to stop construction of the interstate. The lawsuit was dismissed when a judge ruled that the project would not adversely affect the natural environment and that TDOT had followed all necessary procedures.  A lawsuit was also filed by the National Wildlife Federation in 1973 requiring an Environmental impact study after the state determined that the project met federal guidelines exempting it from an EIS. 
Construction began in early 1982. The project required the removal of hundreds of thousands of cubic feet of dirt and rock.  Initially, the parkway was going to be at-grade, but TDOT engineers chose to build it below the surface of the ground to reduce noise and vehicle emissions pollution after citizens in large cities living near interstates had complained of disturbances caused by highway traffic.  The state also agreed to take measures to reduce the impact of the interstate as a further compromise to opposition by such means as beautification, which is the origins of the highway's "parkway" designation, and banning truck traffic. This ban was blocked by a federal court in 1988 after being challenged by multiple trucking organizations.  Engineers chose to construct the highway with concrete rather than asphalt so it would last longer. 
The section between I-24 and I-65 was completed on December 12, 1985, and the section between I-65 and I-40 was completed in April 1987.
 It was the most expensive road, per mile, built in Tennessee at the time, with a total cost of $163 million.
 In the first year the parkway was open, traffic on I-40 decreased by about 16 percent.
speed limit was initially 55 miles per hour (90 km/h). This was later increased to 65 mph (105 km/h), but reduced back to 55 mph after complaints from motorists.
I-440 was built to carry only 64,000 vehicles a day. By 2008, the average annual daily traffic (AADT) was 106,219 vehicles.  The highway experiences back-ups every day during rush hour.  By the 2000s, the highway had begun to develop cracks and potholes, and in 2009 TDOT spent $8 million to rehabilitate the roadway. This included cutting grooves parallel to traffic flow in the lanes to improve traction after the overuse of the roadway had smoothened the surface, causing a susceptibility of vehicles to hydroplane. The highway continued to develop potholes afterwards, and prompted citizens to push for reconstruction of the entire parkway. 
After the Tennessee General Assembly passed the IMPROVE Act in 2017, which increased the state's fuel taxes and vehicle registration fees with the intent of funding a backlog of 962 needed transportation projects, TDOT announced that an upgrade of I-440 was a top priority.  In November 2017 plans were announced to begin reconstructing the entire route the following year, which will include replacing the concrete with asphalt and widening the parkway to eight lanes in most places, replacing the grass median with a median barrier. 
The entire route is in Davidson County.
|Nashville||0.00||0.00||—||I-40 – Memphis, Nashville||Western terminus; I-40 exit 206|
|1.47||2.37||1||Murphy Road||Eastbound exit and westbound entrance|
|1.47||2.37||1A||US 70S (West End Avenue)||Signed as exit 1 westbound|
|2.82||4.54||3||US 431 (21st Avenue South, Hillsboro Pike)|
|Nashville– Berry Hill line||4.82||7.76||5||I-65 – Nashville, Huntsville||One of two four-level stack interchange in Tennessee; I-65 exit 80|
|Nashville||6.29||10.12||6||US 31A / US 41A (Nolensville Pike)|
|7.64||12.30||—||I-24 / I-40 – Nashville, Knoxville, Chattanooga||Eastern terminus; connection to Nashville International Airport; I-24 exit 53; I-40 exit 213A|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
- "Route Log and Finder List - Interstate System: Table 2". FHWA. Retrieved September 24, 2007.
- Deese, Holly (April 8, 2016). "I-440: An $8 million 'cheap fix' gone bad". The Nashville Ledger. Nashville, Tennessee. Retrieved 2017-12-13.
- Williams, William (August 7, 2011). "Interstate 440 turns 25 with a history of successes and setbacks". Nashville City Paper. Nashville, Tennessee. Archived from the original on 15 February 2018. Retrieved 2017-12-14.
- Google (September 16, 2011). "Overview map of I-440 in Tennessee" (Map). Google Maps. Google. Retrieved September 16, 2011.
- Greenberg, Pierce (April 18, 2013). "Interstate 440: The road Nashville loves to hate". Nashville City Paper. Nashville, Tennessee. Archived from the original on 14 December 2017. Retrieved 2017-12-13.
- Nashvillians Against I-440, et. al. v. Andrew J. Lewis, Jr., et. al., 80-3722 (United States District Court, M. D. Tennessee, Nashville Division September 23, 1981).
- Abruzzese, Leo (June 2, 1988). "TENN. TRUCK BAN BLOCKED". Journal of Commerce. New York City. Retrieved 2018-07-01.
- TDOT 2008 AADT Book
- Garrison, Joey (May 9, 2017). "Long-awaited repairs on Nashville's I-440 slated for coming year after gas tax hike". The Tennessean. Nashville, Tennessee. Retrieved 2017-12-14.
- Koehn, Alexandra (November 15, 2017). "Changes Coming To I-440 In Nashville". WTVF. Nashville, Tennessee. Retrieved 2017-12-14.
- TDOT City Map Nashville SW
- TDOT City Map Nashville SE