State Route 400 is a freeway and state highway in the U.S. state of Georgia serving parts of Metro Atlanta. It is concurrent with U.S. Route 19 (US 19) from exit 4 until its northern terminus south-southeast of Dahlonega, linking the city of Atlanta to its north-central suburbs and exurbs. SR 400 travels from the Lindbergh neighborhood in the Buckhead district of Atlanta, at I-85, to just south-southeast of Dahlonega. Like the Interstate Highways, it is a limited-access road, but unlike the Interstates, the exit numbers are not mileage-based, they are sequential. Once SR 400 passes exit 18 (SR 369), it changes from a limited-access freeway into an at-grade divided highway with traffic lights, but still with a speed limit of 65 miles per hour (105 km/h), and ends at the J. B. Jones Intersection at SR 60/SR 115 in Lumpkin County.