O.C.G.A. § 32-6-192

When the department, the county, or the municipality having jurisdiction of a public road determines that it is reasonably necessary and in the public interest to use an underpass or overpass instead of a grade crossing at a new or relocated railroad track or tracks or at a new or relocated public road, the procedure to be followed, the division of costs, and the maintenance responsibilities shall be the same as are provided in Code Sections 32-6-194 through 32-6-198.