Research On The Optimization Of The Warning Zone Length For The Four-lane Freeway

At present,China's expressways are in the period of establishment and maintenance,with the continuous construction and operation of highways,problems of highway construction and maintenance have also arisen,especially for the early four-lane expressway,which has been damaged more severely,and construction work is imminent.The expressway construction work zone is a traffic management area set up for maintenance of the expressway.The construction operation is divided into six zone: the warning zone,the upstream transition zone,the work zone,the downstream transition zone,and the termination zone.The role of the warning zone is mainly to remind the driver of the road construction in front of the construction area,pay attention to the changes in traffic conditions around the construction area,and be careful in driving to take timely measures.The length of the warning zone for expressway construction consists of three parts: the distance from the normal driving of the vehicle to the final speed limit value,the minimum safety distance when the vehicle reaches the end of the warning zone,and the queue length of the vehicle caused by reasons such as the closed lane and the reduction of the number of lanes.Through surveys,drivers tend to change lanes after seeing lane-loss signs.Therefore,the length of the warning zone is set on the basis of vehicle lane-changing characteristics to reduce the queue of vehicles waiting at the end of the warning zone.The vehicle,thereby reducing the delay of the vehicle,increases the speed at which the vehicle passes.In this paper,based on the study of vehicle traffic characteristics in the construction warning zone,the concept of the length of the construction warning zone is proposed to optimize the safety,smoothness,and smooth completion of the vehicle changing task in the construction warning zone as an important consideration for the length of the construction warning zone.Then analyze the driving characteristics of the changing-lane vehicle and build a game model between the changing-lane vehicle and the rear lane of the target lane,and take the psychological security income and time income as the “gain and lose” indicators of both sides of the game.The quantification of psychological security benefits is an important quantitative indicator for the game.The electric field in physics is used to construct the driver's psychological field,and the relevant indicators in the psychological field are calibrated.Next use the constructed model to solve the length of vehicle lane change.There are two parts to the length of the lane change,that is,the distance traveled by the vehicle from the generation of lane change intention to the insertion of the target lane and the distance traveled by the vehicle during the lane change process.The distance traveled during the search for the insertable gap phase is solved by utilizing the characteristics of the distance of the front end of the highway vehicle.For the distance traveled by the vehicle during the lane change process,the game model established in the text is used to divide the vehicle lane change process into several phases.In part,the optimal driving strategy for each part of the vehicle is obtained step by step,and the optimal strategy set of the vehicle in the lane changing process is obtained.At the same time,this part uses the dynamic characteristics of vehicles to change the path of the vehicle in the longitudinal trajectory mathematical modeling,in order to solve the vehicle at any time relative position and angle.Finally,using VISSIM simulation technology to simulate the length of the optimized warning zone,the queue length and delay are used as indicators to verify the rationality of the optimized length of the warning zone.