where does us highway 31 start and end
U.S. Route 31 U.S. Route 31 or U.S. Highway 31 (US 31) is a major north–south highway connecting southern Alabama to northern Michigan. Its southern terminus is at an intersection with US 90/US 98 in Spanish Fort, Alabama. Its northern terminus is at an interchange with Interstate 75 (I-75) south of Mackinaw City, Michigan.