Field evaluation of weigh-in-motion screening on truck weigh station operations

Weigh-in-Motion (WIM) systems can improve the capacity of weigh station operations by screening trucks while traveling at high speeds and only requiring trucks within a threshold of a maximum permissible weight to be weighed on more accurate static scales. Consequently, the operation of a weigh station is highly dependent on the accuracy of the screening WIM system. This paper develops a statistical procedure for relating axle and gross weight accuracies for evaluating the accuracy of a WIM system. In addition, the paper examines the WIM scale operation at the Stephens City weigh station in Virginia to present a case study evaluation of the operation of a weigh station that is equipped with WIM screening. The case study evaluates the accuracy of the WIM technology in addition to the operations of the weigh station in terms of service time, system time, and delay incurred at the static scales.