Stone Mountain Freeway Gwinnett County and have a partial interchange with Park Place Boulevard and Rockbridge Road. Just to the east of this interchange, the freeway ends and US 78/SR 10 continue to the east, locally known as Stone Mountain Highway. West of I-285, the speed limit is . East of the interchange with I-285, the limit rises to . Unlike Georgia's Interstate highways, the highway still has actual sequential exit numbers, rather than being mileage-based. There is no exit 6, which makes the exit numbering non-sequential. All of Stone Mountain Freeway is included as part of the National Highway System, a system
Stone Mountain Freeway counties. Stone Mountain Freeway begins at an interchange with US 29/SR 8 (Lawrenceville Highway) on the Scottdale–North Decatur city line, within DeKalb County. There is no access to US 29/SR 8 north from Stone Mountain Freeway or to Stone Mountain Freeway from US 29/SR 8 south. Southwest of this interchange, US 29/US 78/SR 8 head toward Decatur. Stone Mountain Freeway travels to the northeast, concurrent with US 78 and SR 410. The concurrency has a partial interchange with Valley Brook Road and North Druid Hills Road. Just before leaving Scottdale is an interchange with Interstate 285 (I-285). Part of this