Pavement milling (aka cold planing) is when road construction contractors grind the surface of the road and the bottom layer is exposed before repaving asphalt. This procedure is used for a variety of reasons including:
1) Recycling the old asphalt
2) The curb and gutter lines are level with existing road once complete and ensures proper drainage.
3) Ensures proper clearance for bridges and overhead structures
4) Any road deterioration is removed efficiently
5) There is no need for complicated road leveling courses and the end product is usually based on the quantities estimated.
Pavement milling extends the life cycle of roads and reduces the impact it has on the environment.