U.S. Route 31 in Indiana

U.S. Route 31 in Indiana
State	IN
Route	31
Type	US
Length mi	266.12
Established	1926
Direction a	South
Terminus a	Gulf Coast via Mobile
Direction b	North
Terminus b	International border via Mackinac Bridge

U.S. Route 31 in Indiana U.S. Route 31 traverses Indiana from the Ohio River near Evansville northward to the Indiana–Michigan state line near South Bend, connecting industrial centers, Interstate 70 corridors, and Midwestern manufacturing hubs. The highway links communities such as Indianapolis, Kokomo, Lafayette, and Nashville and serves as a regional arterial for freight movement between the Great Lakes and the Gulf of Mexico. Managed by the Indiana Department of Transportation and featured in planning by metropolitan agencies including the Indianapolis Metropolitan Planning Organization, the route combines freeway segments, expressways, and urban surface streets.

Route description

The route enters Indiana from Kentucky at the Ohio River crossing near Evansville and proceeds north through Vanderburgh County and Pike County toward Bloomington and Monroe County before reaching Johnson County and the Indianapolis metropolitan area. North of Indianapolis it continues past Carmel, Westfield, and Franklin into Howard County and Kokomo. The corridor carries multiple overlapping routes including stretches of U.S. Highway business routes and intersects major corridors such as Interstate 69, Interstate 465, U.S. 52, and U.S. 24. Roadway types vary from rural two-lane segments near Brown County to limited-access freeway sections around South Bend and Indianapolis. The highway provides access to landmarks including Indiana University Bloomington, Lucas Oil Stadium, and Ball State University via connecting routes.

History

Designated in the 1926 nationwide numbering adopted by the American Association of State Highway Officials, the route incorporated earlier auto trails such as portions of the Lincoln Highway and the Dixie Highway corridors that influenced mid-20th-century routing. During the Interstate Highway System era, segments were upgraded, realigned, or bypassed to accommodate growth in Marion County and suburbanization around Hamilton County towns like Carmel and Fishers. Federal programs administered by the Federal Highway Administration and state initiatives led to construction of limited-access sections, particularly the conversion of sections to expressway standards in the 1960s–1990s. Community responses to bypass proposals involved municipal governments such as those of South Bend and Lafayette, and legal frameworks including state statutes guided right-of-way acquisition. Preservation advocates cited historic districts like those in Bloomington and Nashville when contesting alignments.

Major intersections

Key junctions include the crossing at I‑69 near Evansville, the connection to I‑64 and I‑74 approaches, the interchange with I‑465 encircling Indianapolis, and the junction with U.S. 30 and U.S. 24 in northern Indiana. Other significant interchanges are with I‑65 connectors, State Road 37 corridors near Bloomington, and the interchange complex serving South Bend International Airport, University of Notre Dame, and regional freight nodes. County seats intersected include Franklin, Kokomo, and Lafayette, with multimodal transfers to rail corridors operated by companies such as CSX Transportation and Norfolk Southern Railway.

Future and planned projects

Planned improvements reflect statewide priorities by the Indiana Department of Transportation and regional planning authorities including the North Central Indiana Regional Planning Council and the Michiana Area Council of Governments. Projects range from capacity expansions around Fishers and Carmel to interchange modernizations near Tipton and safety upgrades in rural counties like Brown County. Long-range proposals consider completing freeway-grade continuity between Indianapolis and South Bend to support freight flows to ports on the Great Lakes and to integrate with I‑69 and Interstate 80/90 corridors. Funding sources include federal aid from the United States Department of Transportation, state allocations approved by the Indiana General Assembly, and local contributions from counties and metropolitan planning organizations.

Special routes and business loops

Multiple business routes and bypasses were established to serve downtowns bypassed by realignments, including business loops in South Bend, Kokomo, and Lafayette. These special routes intersect historic commercial districts such as South Bend Civic Theatre districts, Kokomo Courthouse Square, and the downtown Lafayette waterfront. Designations have changed over time under guidance from the AASHTO and state highway commissions; some former alignments now function as county roads or state-designated connectors managed by the INDOT.

Traffic volume and roadway characteristics

Traffic volumes along the corridor vary widely, with high annual average daily traffic counts within Marion County near Indianapolis and lower counts in rural stretches of Brown County and White County. Roadway characteristics include limited-access freeway design, controlled-access expressway standards, and two-lane rural arterial segments with asphalt or concrete pavements maintained according to INDOT pavement management practices. Freight traffic, measured at count stations used by the FHWA, reflects connections to manufacturing centers such as Aerospace Industries facilities near Muncie and automotive suppliers clustered around Elkhart County and St. Joseph County. Safety programs have targeted intersections with high crash rates near suburban growth areas in Hamilton County and corridor-wide initiatives integrate with statewide traffic operations centers in Indianapolis.

Category:U.S. Highways in Indiana