Design standards for entrance ramp geometrics are based upon the measured acceleration performance of vehicles. To date, the data most widely used for design purposes is presented in AASHO, A Policy on the Geometric Design of Rural Highways, (1965), from tests conducted prior to 1940. A need has been expressed to update design criteria based upon our present vehicle characteristics. In order to review design standards based on the AASHO or Matson acceleration curves, acceleration rates of current vehicles are required. This paper describes an investigation of a technique to measure vehicle acceleration rates on ramps. Acceleration rates obtained from this study are compared with both the AASHO and Matson acceleration curves. This comparison indicates the applicability of these two curves with respect to current vehicle performance characteristics. (A)
Samenvatting