In a mill-and-overlay, the distressed surface layer is ground off to a controlled depth, then a fresh asphalt surface is paved in its place. Milling keeps the finished grade correct at curbs, gutters, and building entrances, and the millings are recycled into new asphalt or reused as base material.
This method restores a smooth, uniform surface efficiently, but only when the base beneath is still doing its job. It is a surface solution, not a structural one.
