In Mississippi a maximum speed limit of 70 mph (113 km/h) is allowed on rural freeways. Only the Interstates (except I-110), U.S. Highway 78, Mississippi Highway 304, and a portion of U.S. Highway 82 have speed limits of 70 mph (113 km/h), with these lengths making up approximately 86% of the state’s freeway mileage.
A speed limit of 65 mph (105 km/h) is typically used on the state’s four-lane divided highways, which include parts of the following roadways: U.S. Route 45 / U.S. Route 45 Alternate, U.S. Route 49 / U.S. Route 49W, U.S. Route 61, U.S. Route 72, U.S. Route 82, U.S. Route 84, U.S. Route 90, U.S. Route 98, U.S. Route 278, MS 15, MS 19, MS 25, MS 39, MS 57, MS 63, MS 67, MS 302, MS 605, MS 607.
A speed limit of 60 mph (97 km/h) is typically used in urban areas where a higher speed limit might be used, but traffic or geometric conditions constitute a lower speed limit, including the following areas: Interstate 20 in Vicksburg, from Jackson to Pearl, and Meridian, Interstate 55 from Jackson to Ridgeland, Interstate 59 in Laurel and Meridian, U.S. Route 61 in Tunica Resorts, U.S. Route 78 in New Albany, U.S. Route 82 in Columbus.
Mississippi has a minimum speed of 30 mph (48 km/h) on four-lane U.S. highways when no hazard exists. The minimum is 40 mph (64 km/h) on Interstate Highways and on four-lane U.S. designated highways that have a 70 mph (113 km/h) speed limit.