This method removes 50mm of existing asphalt, which is then replaced with new asphalt. This method allows for the replacement of asphalt without increasing the a roadway's elevation.
Milling removes surface deficiencies and is used predominantly in urban situations where curb and gutter are present and road elevation is critical for drainage considerations. The milled material is used to surface gravel roads throughout the City.
A variation of this method involves the milling of the area adjacent to the curb and gutter, but not milling the asphalt from the majority of the roadway. This allows for the overlay to meet the curb elevation, but does not incur the cost of a full milling operation.