It serves as a connector between US 11 / US 41 / US 64 / US 72 and SR 148 and the Lookout Mountain tourist area.

SR 318 begins in the Tiftonia/Lookout Valley area of West Chattanooga at US 11/US 41/US 64/US 72.

It is a narrow, winding mountain road that rises above the U.S.

It ends at SR 148 north of the town of Lookout Mountain and the route travels near the eponymous mountain ridge of the same name.

The entire route is in Hamilton County.