Design of Secondary and Subdivision Roads in Virginia Based on Thickness Equivalency Values

About the report:

The design of secondary and subdivision roads in Virginia is based on the design charts recommended by the Highway Department. In view of recently gained knowledge of materials and design techniques, the Pavement Research Advisory Committee requested that a new design procedure for these roads be developed. In the proposed design developed, the soil support value of the subgrade has been evaluated in terms of soil resiliency and CBR values. Soil resiliency values for any part of Virginia are given in the report or could be easily determined. The design is based on average daily traffic with 0 to 5 percent trucks. Provision has been made in the design for increased truck traffic. The proposed design method is based on the AASHO Road Test Results (1962) now being used in many states, including Virginia. This design was arrived at after personal interviews with the district materials engineers and the evaluation of the designs recommended by them during the last twelve months. In essence, the same pavement designs could be obtained by using the proposed method or the present design charts. However, this method provides the designer more choices in the uses of materials and thus may lead to economies.

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