The Metropolitan Expressway Public Corporation (MEPC) constructed a vehicle detector maintenance support system with a view to improving the accuracy of collected data. The system has the following functions: (1) Evaluation of data accuracy requires the determination of a traffic volume criterion value. Traffic volume data from detectors located at several cross-lane detection points along each section of roadway are processed using the root-mean-square method to determine the average traffic volume with an error margin of 3%. By comparing the traffic volume value obtained for each cross-roadway detection point with he representative traffic volume value, the system enables identification of detection points whose data are inaccurate by a margin of 5% or more; and (2) Prior to the maintenance of detectors whose data accuracy is low, the system provides information on detector maintenance requirements. This information is prioritized in accordance with the degree to which abnormalities are likely to impede traffic control system functions such as the evaluation of road congestion.
Abstract