Study Of Multi-truck-type Adaptive Control Weigh-in-motion Threshold Adjustment System And Simulation

Overload transport is a comprehensive social issue which causes a great loss. It is critical to reduce the destruction of road and ease road congestion caused by overload vehicles with scientific and reasonable methods. Based on the theory of dynamic overload control technology,the paper puts forward the adaptive WIM threshold adjustment system installed at the entrance of main highway. The system can turn the traditional fixed threshold of weight-in-motion system into dynamic weight value,in order to achieve the goal that managing trucks dynamically through the change of traffic volume.Firstly,multi-truck-type dynamic weight threshold model adapted to our country is introduced in this paper. The trend of truck overload volume is analyzed by randomly sampling,and the measure to choose appropriate values of threshold incremental in multi-truck-type dynamic weight threshold model is derived.Secondly,based on the characteristics of the practical application of the overload management stations and multiple models adaptive overload control technology,the paper proposed that adaptive overload management station should be set at highway entrance. The layout scheme and the working process of the overload control station of the highway toll and a common trunk highway is designed.Thirdly,queuing model is developed according to Markov state transition process by analyzing the operating characteristics of the vehicles in different weight stations layouts. Compared with practical application characteristics of weight station and multiple models adaptive overload control technology, the traffic conditions of starting the dynamic weight threshold model in WIM system is put forward based on queuing model at weight stations. Then the multi-truck-type adaptive weigh-in-motion threshold adjustment system is established.Finally,the process of overload control technology is simulated by VISSIM simulation system under two different station layouts and traffic demands. VisVAP programming is used to control the state of weight station and change the weighing threshold of the weight station according to the different queue length. The results demonstrate that adaptive WIM threshold adjustment system yields higher violator capture percentage and less delay compared with fixed threshold scenario. The technology will alleviate overloading and improve road conditions effectively. In additions,the simulation results suggest that the application of new layout can obtain a higher capture percentage and less travel delay for non-overload trucks comparing with the existing layout.