The Ridge in Ridgeville on SR 99 is listed on the National Register of Historic Places.

[citation needed] SR 99 begins at an intersection with US 82/SR 520 in southern Glynn County.

The road follows a northeast direction but after the bridge over Fancy Bluff Creek makes a reverse curve to the left before an intersection with SR 32 just west of Sterling.

SR 99 continues north through rural Glynn County to an intersection of SR 25 Spur south (Golden Isles Parkway), then to a interchange with Interstate 95 (I-95) at exit 42 and on to US 17/SR 25 in northern Glynn County.

In Eulonia, SR 99 once again intersects US 17/SR 25, where it continues west 1 mile (1.6 km) more to its northern terminus at another interchange with I-95 at exit 58.

Also, a central segment of SR 131 was designated from US 25/US 341/SR 27 southwest of Darien to US 17/SR 25 south-southwest of that city.

Also, the western terminus of the central segment was shifted south-southwest to connect with SR 32 at US 25/US 341/SR 27 north-northwest of Brunswick.

The interchange with I-95 has been reconstructed to accommodate four through lanes of traffic on SR 99 and by 2030, the 6-mile-long (9.7 km) portion between I-95 and US 341 is scheduled to be widened to a four-lane divided highway.

The Georgia Department of Transportation plans to ultimately widen the entire segment between US 17/SR 25 and US 82/SR 520.