Georgia State Route 400 is a major highway in the state of Georgia, primarily serving the northern suburbs of Atlanta. It runs approximately 30 miles, connecting I-285 to Dahlonega, and is known for its role in facilitating commuter traffic in the region. The route features several interchanges with other major roads, including I-85 and GA-141. It is a vital corridor for both local and regional travel, providing access to various commercial and residential areas, as well as recreational sites in the nearby North Georgia Mountains.