Interstate 155 (Missouri–Tennessee)

Interstate 155 (I-155) is an east–west auxiliary Interstate Highway that runs 26.77 miles (43.08 km) through the Bootheel of Missouri and the northwestern corner of Tennessee. It begins south of Hayti, Missouri at Interstate 55 (I-55) and passes eastward through Caruthersville, before crossing the Mississippi River on the Caruthersville Bridge into Tennessee. The route then proceeds to Dyersburg, where it terminates at an interchange with U.S. Route 51 (US 51). I-155 is the only piece of surface transportation infrastructure that directly connects Missouri and Tennessee, and is concurrent with US 412 for its entire length.

A proposal for a bridge between Missouri and Tennessee arose in the late 1930s, at which point the two states were two of the last remaining contiguous states not connected by road or rail. After the Interstate Highway System was established in 1956, this proposal began to be incorporated into a larger proposal for a new Interstate Highway linking I-55 in Hayti to I-40 in Jackson, Tennessee. In 1964, the federal government approved the westernmost portion of this freeway, designating it as I-155, but did not approve the entire route to Jackson. Construction on the Caruthersville Bridge began in 1969, and the bridge, along with the Missouri portion of the route, opened in 1976. The last portion of I-155, located in Dyersburg, was completed in 1979.