U.S. Route 31 in Indiana

U.S. Route 31
US 31 highlighted in red; unsigned portion on beltway in orange
Route information
Maintained by INDOT
Length	266.02 mi (428.12 km)
Existed	October 1, 1926[1]–present
Major junctions
South end	US 31 at Kentucky state line
Major intersections	I-65 Toll in Jeffersonville I-65 in Crothersville I-65 in Taylorsville I-74 / I-465 / US 36 / US 40 / SR 37 / SR 67 in Indianapolis I-65 in Indianapolis I-74 / US 421 in Indianapolis I-70 in Indianapolis I-69 / SR 37 in Indianapolis I-465 / US 52 / US 421 in Carmel I-80 Toll / I-90 Toll / Indiana Toll Road in South Bend
North end	US 31 at Michigan state line
Location
Country	United States
State	Indiana
Counties	Clark, Scott, Jackson, Bartholomew, Johnson, Marion, Hamilton, Tipton, Howard, Miami, Fulton, Marshall, St. Joseph
Highway system
United States Numbered Highway System List Special Divided Indiana State Highway System Interstate US State Scenic
← US 30 → SR 32

U.S. Route 31 (US 31) is a part of the United States Numbered Highway System that runs from Spanish Fort, Alabama, to Mackinaw City, Michigan. It enters the U.S. state of Indiana via the George Rogers Clark Memorial Bridge between Louisville, Kentucky, and Clarksville, Indiana. The 266.02 miles (428.12 km) of US 31 that lie within Indiana serve as a major conduit. Some of the highway is listed on the National Highway System. Various sections are rural two-lane highway and urbanized four- or six-lane divided expressway. The northernmost community along the highway is South Bend near the Michigan state line.

US 31 was first designated as a US Highway in October 1926. A northern section (from Rochester to South Bend) and a far southern section (on old US 31W into Louisville on the K&I Bridge) of the highway originally served as part of the Dixie Highway. US 31 was the Jackson Highway from Indianapolis to Seymour. US 31 replaced the original State Road 1 (SR 1) designation of the highway which dated back to the formation of the Indiana State Road system. SR 1 ran from Clarksville through Indianapolis to South Bend and ended at the Michigan state line.