Legal Basis for Trafficway Requirements at Weight-in-Motion Control System Points

Reliability and accuracy of weighing a moving vehicle by automatic weight-in-motion (WIM) control systems depend on transport and trafficway performance. The experience in using WIM control systems on regional roads shows significant shortcomings in weighing accuracy due to low requirements for smoothness and structural strength of pavement in places of their location. Road irregularities cause additional dynamic loads on the road pavement and weighing sensors. The formation of ruts provokes lateral vibration of trucks, which is critically unacceptable in the area of WIM control system points and reduces the reliability of weighing results. The data analysis of violations registered in the Volgograd Region shows that about 10 % of trucks moving on regional highways exceed the permissible weight by 20 %. This leads to accelerated wear of the road pavement and defect formation. Purpose : Substantiation of requirements for road pavements at WIM control system points and on approaches to them with regard to operation of the weighing equipment. Methodology/approach : The analysis of actual conditions of the road pavement, assessment of the live load on the weight sensors, calculation of the minimum permissible values of the elastic modulus, rut depth and longitudinal evenness. Investigations are carried out with respect to sensor specifications and requirements for their operational safety. Research findings : The maximum rut depth, elastic modulus of the road surface are substantiated, and requirements are presented for the permissible longitudinal evenness at WIM control system points and on adjacent road sections.