APPLICATION OF IN-MOTION WEIGHING USING INSTRUMENTED BRIDGES

Truck weight data are needed by several agencies within state or national highway departments. This paper contains a description of how these data can be obtained in an undetected manner at highway speeds by using instrumented highway bridge girders with a portable or semiportable bridge weigh-in-motion system. Information on the concept and accuracy is presented along with correlation data obtained with vehicles that were weighed on a static scale. Applications are outlined for planning, pavements, bridge engineering, and enforcement purposes. A discussion is presented of the inaccuracies in predicting equivalent single axle load values caused by the variability present in any weighing system.