Georgia Code Title 32. Highways, Bridges, and Ferries § 32-4-21

Whenever the board, or the commissioner when the board is not in session, deems it necessary and in the public interest to have a new or existing public road designated as part of the state highway system, whether as additional mileage or as part of a substitution or relocation, the board, by resolution, or the commissioner, by written notice to the board, may designate such road to be a part of the state highway system. If the road proposed to be designated is a part of either a county road system or a municipal street system, the department shall give written notice to the county or municipality of the effective date that such road shall become part of the state highway system. Any change on the state highway system by designation shall be recorded on the official map and in the written records of the state highway system, as provided for in subsections (a) and (b) of Code Section 32-4-2.