It is located entirely in Middle Tennessee and except for the Lewisburg bypass, where it is concurrent with Tennessee State Route 106 (SR 106), it is entirely concurrent with unsigned SR 11.

It is concurrent with unsigned State Route 11 (SR 11) for its entire length.

South of Columbus, US 31A went through Jonesville, then passed through an interchange with Interstate 65, and terminated at US 50 in Seymour, Indiana.

It first appears on the 1964 Indiana State Highway Commission map (the previous edition shows a red line denoting a U.S. route but no marker) and last appears on the 1967–68 edition.

Joseph Valley Parkway interchange on the south side of the city, joining SR 933 south of downtown, then turns west along Cleveland Road just north of the Indiana Toll Road (Interstate 80/90) to return to US 31.