South Vine Street links the northern and southern portions of Paso Robles, California. The pavement of the roadway was in distress, curbs had fallen down slopes, and three areas of discernable settlement had occurred. The City desired to reconstruct the roadway economically while still enhancing the flow of vehicle and bicycle traffic.

Earth Systems was retained by the design engineer to evaluate the existing roadway condition and prepare a soils engineering report for roadway reconstruction. Aspects of our report included retaining structures, utilities, and reconstruction of the roadway. Typical roadway reconstruction projects involve removing the existing asphalt concrete and aggregate base to provide for a new roadway section to be constructed. During our evaluation, we determined that the existing aggregate base and sub-base were generally of adequate thicknesses where the road would remain at the same elevation or raised. The deteriorated asphalt concrete, estimated to be approximately 50 to 60 years old, was deteriorated beyond repair. South Vine Street reconstructed with new and reused aggregate base roadway bordered by red bike lanes.In lieu of hauling the existing asphalt concrete to a nearby dump or recycling yard, which would have involved numerous truckloads, it was decided upon by the design engineer and City staff to attempt to use pulverized existing asphalt concrete as new aggregate base. We performed preliminary grinding tests and determined that the material could meet necessary standards for aggregate base. As a result, the contractor utilized a large roto-milling machine to pulverize the existing asphalt concrete to be used as aggregate base for the new roadway section. This step saved numerous truck trips, helped reduce traffic, and reduced the amount of virgin aggregate base needed for the project. The resulting reconstructed South Vine Street is a roadway that enhances the Paso Robles lifestyle, from an environmental and aesthetic standpoint.