Interstate 155 (Missouri–Tennessee)

Interstate 155 (I-155) is an east–west auxiliary route of Interstate 55 (I-55) that runs through the Bootheel of Missouri and the northwestern corner of Tennessee. It begins south of Hayti, Missouri, at I-55, passes eastward through Caruthersville, and crosses the Mississippi River on the Caruthersville Bridge into Tennessee. The route then proceeds to Dyersburg, Tennessee, where it terminates at U.S. Route 51 (US 51). I-155 is the only road that directly connects Missouri and Tennessee, and is concurrent with US 412 for its entire length.

Route description
Interstate 155 begins at a near-full cloverleaf interchange with I-55 in Pemiscot County, Missouri, on the edge of Hayti, where US 412 continues as a four-lane divided highway to the northwest. Initially traveling in a southeastward direction, the interstate passes through farmland in a sparsely populated rural area. A few miles later, the highway passes south of Caruthersville where it has an interchange first with a local road, and then with the southern terminus of Route 84 near the Caruthersville Memorial Airport. A few miles later, the highway shifts south-southeast before crossing the Mississippi River on the 1.35 mi Caruthersville Bridge into Dyer County, Tennessee.

Upon crossing the river, I-155 veers east-southeast and reaches an interchange with State Route 181 (SR 181), which is part of the Great River Road. Passing through additional farmland, the interstate crosses the Obion River a few miles later and has an interchange with SR 182 a short distance beyond south of the Lenox community. The highway then ascends out of the Mississippi Alluvial Plain on to the Gulf Coastal Plain and enters a wooded area, where the Tennessee Welcome Center is located, before reaching Dyersburg a few miles later. Traveling along the northern fringes of the city in an eastward direction, the interstate has an interchange first with SR 78, which also provides access to Tiptonville. A few miles later, the interstate turns northeast, before reaching a trumpet interchange with US 51, where the I-155 designation ends, and US 412 splits off to the south towards Jackson. The route continues to the northeast as a controlled-access segment of US 51.

Background and planning
Prior to the construction of the Caruthersville Bridge, a number of ferries crossed the Mississippi River between the two states. By the early 1940s, Missouri and Tennessee were two of the few remaining bordering states in the country which were not directly connected by road or rail, and a bridge across the river began to be proposed. A committee was created by both state legislatures to study the possibility of constructing a bridge near Caruthersville in 1949. The bridge site was chosen by the commission on November 18, 1952, which was subsequently approved by the Army Corps of Engineers on August 20, 1953.

After the passage of the Federal Aid Highway Act of 1956, which authorized the Interstate Highway System, officials in Missouri, Tennessee, Kentucky, and Illinois began an effort to improve connectivity between the four states, which included a westward extension of I-24 from its allocated terminus in Nashville to southern Illinois. Governors John M. Dalton of Missouri and Buford Ellington of Tennessee announced on January 30, 1962, a proposal for a new Interstate Highway between I-55 in Hayti and I-40 in Jackson, Tennessee, which would incorporate the bridge. On September 17, 1963, the governors of the four states met with President John F. Kennedy where they reached an agreement on the alignment for the I-24 extension and endorsed the routing for the Hayti-to-Jackson Interstate Highway. On August 18, 1964, the Bureau of Public Roads, the predecessor agency to the Federal Highway Administration (FHWA), approved the I-24 extension and authorized an Interstate Highway spur route between Hayti and Dyersburg, which was named I-155. However, they did not give approval to the entire proposed route to Jackson.

Construction
Construction of I-155 began with the contract for the Caruthersville Bridge piers, which was announced to have been awarded on March 20, 1969. Preliminary work began with construction of an access road to the site in June 1969, and work on the first pier was underway three months later. The contract for the construction of the 1,030 ft bridge approach on the Missouri side was awarded in December 1971, and the contract for the 2,480 ft Tennessee approach was awarded in December 1972. Both projects experienced delays due to flooding and erosion in 1973. The contract for grading and construction of bridges for the stretch between the Tennessee approach and SR 182 was awarded in January 1973. This project required the construction of an artificial levee within the Mississippi River flood plain, which proved to be one of the most difficult jobs undertaken by TDOT. This work was completed by the end of 1975, after multiple delays. In Missouri, the contract for construction of the section between I-55 and Routes D and U was let in May 1974, and the adjacent section extending to the Mississippi River approach was awarded two months later. The design work for the section between SR 182 and US 51 was not approved prior to the enactment of the National Environmental Policy Act of 1969, and required an environmental impact statement (EIS). A draft EIS was approved by the FHWA on September 30, 1974.

On December 1, 1976, the Caruthersville Bridge was dedicated and opened to traffic in a ceremony by Missouri Governor Kit Bond and Tennessee Governor Ray Blanton. The entirety of I-155 in Missouri and the Tennessee section extending to SR 182 were also opened on this day, with the latter section restricted to two lanes to allow for completion of final paving. This paving work was scheduled for completion by October 1, 1977. The first contract for the section between SR 182 and the eastern terminus with US 51/412 was awarded in August 1975, and this section was completed in November 1979, after several delays.

Later history
While the Interstate Highway between Dyersburg and Jackson was never approved, TDOT continued to explore options to upgrade this stretch of highway, which was then only SR 20. The first major proposal was for a toll road throughout the 1970s. On June 22, 1980, the American Association of State Highway and Transportation Officials established US 412 along I-155 as part of a route between Jackson and Walnut Ridge, Arkansas. On June 14, 1985, the FHWA approved a draft EIS for the upgrade to US 412, which included the possibility of constructed the route as a fully controlled-access highway or a four-lane highway without access control. The upgrade was one of six freeway projects including in Governor Lamar Alexander's Better Roads Program in 1986, referred to as "Bicentennial Parkways", and was referred to in the initial plans as the "Interstate 155 Extension". Unlike all of the other freeway projects, however, the US 412 upgrade was instead constructed as a limited-access four-lane highway with a combination of interchanges and at-grade intersections. This took place between 1989 and 1995.

An extension of Interstate 69 through Tennessee was proposed under the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA) as part of a corridor to facilitate trade between Canada and Mexico. This extension was further spearheaded by the enactment of the North American Free Trade Agreement (NAFTA) in 1994. This extension, sometimes considered part of the unofficial NAFTA superhighway, was proposed to interchange with I-155 northwest of Dyersburg, replace the remainder of the route to its eastern terminus, and continue onto the US 51 freeway This proposal would reduce the length of I-155 by approximately 8 mi; however, it is unclear whether or not this extension of I-69 will ever be built.