SR 315 begins at an
intersection with
SR 219 in
Piney Grove, in
rural southwestern
Harris County. At this intersection, the roadway continues to the southwest as Goat Rock Road. SR 315 travels to the northeast and immediately curves to the north-northeast. It curves back to the northeast to an
interchange with
Interstate 185 (I-185;
Chet Atkins Parkway). The route then gradually curves to a roughly eastward direction, traveling through
Mulberry Grove. After that, it curves to the south, to a very brief
concurrency with
US 27/
SR 1 in
Cataula. East of town, at the intersection with the southern terminus of Lynn Drive and the southwestern terminus of Denney Road, next to Clowers Cemetery, SR 315 turns right and travels to the south-southeast. Southwest of
Ellerslie, the highway intersects the northern terminus of Old Warm Springs Road. It turns left onto Warm Springs Road and travels north-northeast for approximately . It curves to the northeast and then to the east-southeast and intersects
US 27 Alt./
SR 85 (Manchester Expressway). The three highways travel concurrently to the north-northeast and enter Ellerslie. At the intersection with Talbotton Road, the highway turns right, to the southeast, and very gradually curves to the northeast, and traveling through
Ridgeway, before it enters
Talbot County. There, it travels through
Baughville, before meeting its eastern terminus, an intersection with
SR 208 (Tuck Persons Highway) in
Olive Branch, west of
Talbotton. ==Major intersections==