U.S. Federal Route 40 is an east-west highway in Southeastern Howard County. It runs from the Boone/Howard County Line, near Rocheport, to the Copper/Howard County Line at Boonville. U.S. Rt. 40 passes through the following town in Howard County. Old Franklin
WB U.S. Rt. 40/MO St Rt 240 at the Boone/Howard County Line. A guide marker in Rochport. A junction marker on NB SPUR MO St Rt 240. WB U.S. Rt. 40/MO St Rt 240 west of Rochport. WB U.S. Rt. 40 near MO St Rt 240. WB U.S. Rt. 40 near ALT MO St Rt 240. EB U.S. Rt. 40/NB MO St Rt 5 in Old Franklin.