States traversed: Indiana, Kentucky, Tennessee, Alabama, and Florida
US Route 231 is a long three-digit route, running from a point in northwest Indiana near Chicago, to Panama City, Florida, on the panhandle's Gulf Coast. The northern end is at US Route 41 in St. John, Indiana. From there, US Route 231 runs east through Crown Point and southeast through Lafayette. US Route 231 heads south from Lafayette through western Indiana, but not westernmost Indiana (that's US Route 41's job). In Kentucky, US Route 231 runs along side Interstate 165 from Owensboro to Bowling Green. The highway continues southeast past Bowling Green to cross into Tennessee, where it serves as the next longitudinal highway east of the central corridor traversed by Interstate 65 and US Route 31 that includes Nashville. US Route 231 stays east of Interstate 65 into Alabama, passing through Huntsville, Pell City, and the east side of Montgomery. Past Montgomery, US Route 231 bows southeast to Dothan and south to Panama City, where it ends at US Route 98.