The highway serves as both the northern and southern frontage roads between exits 11 and 16 along Interstate 85 (I-85) and U.S. Route 80 (US 80).

Prior to US 80's realignment onto I-85 in November 2010, SR 126 was only the northern frontage road.

SR 126 begins at itself, a consequence of the realignment as it forms a complete loop.

The route north of I-85 is the original section of the highway.

When US 80 was rerouted onto I-85, SR 126 was extended to travel along the original route of US 80, which was the roadway paralleling the northbound lanes of I-85.