Test of WIM sensors and systems on an urban road

This paper describes a large-scale test of six WIM systems and four additio nal sensors on an urban roadway in Zurich, Switzerland. Gross weights from some thousands of statically weighed vehicles were used to determine the le vels of accuracy for each system, with reference to the new draft of the Eu ropean specification on WIM (COST323). The accuracy of axle weights was not tested. The WIM sensors, which included one prototype, were tested with th e assistance of a recording and processing device supplied by the organiser . Most systems encountered some problems, failures and faults, under the ca refully controlled conditions of the 30-month test. However, these were gen erally solved by the suppliers after some delay. Statistics are provided on overall levels of accuracy and on trends with se ason and time. In addition, a brief history of system malfunctions and fail ures is provided. Nevertheless the scope of the conclusions is limited by t he traffic conditions and the test plan.