U.S. Federal Route 31 is a north-south highway in Howard County. It runs from the Miami/Howard County Line, near Cassville, to the Howard/Tipton County Line, south of Kokomo. U.S. Rt. 31 passes through the following towns in Howard County. Cassville Kokomo
U.S. Rt. 31 is multi-plexed in Howard County. U.S. Rt. 35, at Kokomo.
U.S. Rt. 31 intersects the following highways in Howard County. Indiana State Route 931, at Kokomo.