The roadway is milled and then resurfaced with two inches or more of new asphalt.
Asphalt resurfacing or overlays are used on higher-volume roads or lower-volume streets that have deteriorated to a point that a chip seal or other pavement preservation treatments are no longer effective. An overlay typically requires some level of removing the existing surface by grinding, either along the edge or the full width of the street, depending on the condition of the street.
The overlay process generally occurs in several phases:
- Removal and replacement of deteriorated curbs and gutters, as well as reconstruction of selected sidewalk ramps to conform to Americans with Disabilities Act (ADA) criteria.
- Milling of the roadway surface.
- Actual resurfacing of the road with new asphalt, combined with re-striping.
The overlay process at times may include a phase to remove and patch some areas of the street that have extensive wear or damage beyond the surface of the pavement. The existing asphalt pavement and subgrade are removed from the roadway and then reconstructed with six to eight inches of new asphalt pavement.
At times, streets deteriorate to a point that requires total reconstruction of the pavement structure. Streets requiring reconstruction will typically require similar steps as an overlay, with pedestrian ramp and curb and gutter repair, but the entire pavement structure is removed, the subgrade is reconditioned and new asphalt and striping is completed.