Known for most of its length as Plantation Road, the state highway runs 6.00 miles (9.66 km) from U.S. Route 221 (US 221), US 460, and US 220 Alternate in Roanoke north to Interstate 81 (I-81) and US 220 near Hollins.

SR 115 begins at an intersection with Orange Avenue, which carries US 221, US 460, and US 220 Alternate, in the northeastern part of the city of Roanoke.

The state highway heads north as two-lane undivided Hollins Road between an industrial area that lines Norfolk Southern Railway's Roanoke District to the west and a residential area to the east.

The state highway leaves the city of Roanoke and enters Roanoke County by crossing Carvin Creek, a tributary of Tinker Creek, south of its intersection with SR 625 (Hershberger Road), which becomes SR 101 to the west.

The state highway expands to a five-lane road with a center left-turn lane and passes through an industrial area on its way to its northern terminus at a diamond interchange with I-81 and US 220.