The roads we drive on are structures, much like buildings. Drivers and cyclists are primarily concerned with the condition of the top layer of the structure, but it takes the entire system to make it function properly. For asphalt concrete roads, as opposed to Portland cement concrete roads, the structural layers of the road, starting at the bottom and building up, are:
- Soil sub base
- Aggregate base (compacted stone)
- Asphalt base course (larger aggregate in the mix)
- Asphalt wearing course, fine aggregate in the mix for smoothness and to prevent moisture penetration
In the case of the 700 to 1100 blocks of Orange Avenue, there are areas where the road's aggregate base course is failing. This weakness in the pavement structure's foundation results in distressed pavement at the surface; evidenced by potholes, ruts, and depressions in the pavement.
The current work repairing the potholes, being performed by the Public Services team, addresses immediate safety and quality of service concerns, but it does not resolve the underlying issue. Until the structure's foundation is repaired, potholes and cracks will continue to arise.
The City worked with the California Department of Transportation over the past four years to schedule and fund a pavement structure rehabilitation project for Orange Avenue. This project was included in Caltrans' current fiscal year budget and has been designed, completed, and awarded. Due to seasonal traffic concerns, the work is planned to begin in late September 2018. In the interim, the current surface patches will provide the residents and guests of Coronado with a safe driving experience.