Georgia Highway 400

State Route 400
Map of northern Georgia with SR 400 highlighted in red
Route information
Maintained by GDOT
Length:	53.70 mi (86.42 km)
Existed:	1971, 1993 – present
Major junctions
South end:	I‑85 in Buckhead
	I‑285 / US 19 in Sandy Springs SR 20 in Cumming SR 369 in Cumming SR 53 in Dawsonville
North end:	US 19 / SR 60 / SR 115 south-southeast of Dahlonega
Location
Counties:	Fulton, Forsyth, Dawson, Lumpkin
Highway system
Georgia State Routes Interstate U.S. State ← SR 388 SR 401 →

I‑285 / US 19 in Sandy Springs
SR 20 in Cumming
SR 369 in Cumming

Georgia state route 400 (officially "SR 400", nearly always Georgia 400 to the public) is a controlled-access state highway in the northern part of the U.S. state of Georgia. It is concurrent with U.S. Route 19 (US 19) from exit 4 (Interstate 285) until its terminus south-southeast of Dahlonega, linking the city of Atlanta to its north-central suburbs and exurbs. Georgia 400 travels from the Lindbergh neighborhood in the Buckhead district of Atlanta, at Interstate 85 (I-85), to just south-southeast of Dahlonega. Like the Interstate highways, it is a limited-access road (with interchanges instead of intersections), but unlike the interstates (which were renumbered by GDOT in 2000), the exit numbers are not mileage-based, they are sequential. Once Georgia 400 passes exit 17 (Georgia 306), it changes from a limited-access freeway into an at-grade divided highway with traffic lights, but still with a high speed limit of 65 miles per hour (105 km/h), and ends at the J.B. Jones Intersection at Georgia 60/Georgia 115 in Lumpkin County.