U.S. Route 231 (US 231) is a north-south U.S highway that is a parallel route of US 31. It runs for from St. John, Indiana, at US 41 to south of US 98 in downtown Panama City, Florida. One of its most notable landmarks is the William H. Natcher Bridge, a long cable-stayed bridge that connects Rockport, Indiana, to Owensboro, Kentucky, spanning the Ohio River. Route description Florida In Florida, US 231 is paired with unsigned State Road 75. The southern terminus is at Business US 98 (unsigned State Road 30) in downtown Panama City. The highway is carried by Harrison Avenue until its intersection with US 98. Continuing north, US 231 passes through Youngstown, Fountain, Alford, Cottondale, and Campbellton before entering Alabama. Major intersections include Business US 98, US 98, SR 77, SR 20, Interstate 10, US 90, SR 73, SR 273, and SR 2. Alabama In Alabama, US 231 is an alternate north-to-south route to Interstate 65, the main north-to-south thoroughfare in the state. U.S. Route 231 serves the east-central part of the state, with I-65 further west and US 431 further east. While both US 231 and US 431 connect the major cities of Dothan and Huntsville, US 231 has a shorter route through fewer cities and terrain changes, avoiding the mountainous cities of Albertville, Gadsden, Oxford, and Heflin. However, there are some mountainous cities along the route, such as Arab and Oneonta. U.S. Route 231 is divided along two-lane roads, three-laned roads, and four-laned undivided and divided highways. The entire stretch south of Montgomery is four-laned, mostly divided with some undivided stretches; as it is a critical connector in the National Highway System, which is a very important web of highways critical to U.S. infrastructure. The stretch between Arab and the state line is an almost entirely four-lane divided highway. Through Huntsville, Alabama, the route functions as Memorial Parkway - the main north-to-south freeway through downtown. The road is a freeway with frontage roads and Texas U-Turns, with some stretches with six lanes plus a frontage road exit lane in each direction. In the medical district of Huntsville, the freeway gains US 431 and loses the SR 53 designation. The road widens to ten lanes on the south side of Interstate 565, with the gained lanes used as access lanes for US 72 or I-565. On the north side of I-565, the road once again goes