Research On Driving Brhavior Characteristic And Control Strategy Of Weaving Area Under Urban V2V/V2I Enviroment

Traffic flow change path and directions at weaving area making road network connected and access to each other, while it cause tremendous traffic conflicts and unstable chaos, also make weaving area the key node. Compared with road sections, traffic capacity and efficiency reduced significantly, weaving area has been an important hotspot of traffic engineering study all the time. In urban area expressway, merging entrance and exit ramps are always very close, usually within 200 meters. Statistics show that 9 of top 10 most congested spots are located nearby weaving area. Cooperative vehicle infrastructure system, CVIS makes interactive communication between vehicles and vehicles, roadside infrastructure and vehicles. Thanks to CVIS which makes providing safety warning, cooperate control, maxim usage of road resource in a certern wide of area possible. For these above reasons, This study focus on driving behavior characteristics under urban expressway, presents a control strategy under mixed traffic of normal vehicle and automated vehicles at urban expressway weaving area.Weaving area is kind of complicated merging area, can be devided into sevral merging zones. Control strategy study usually focus on freeway on ramp merging, there is not much discussion about merging and exit combined or weaving area and interference in short distance. Control strategies considered gap and safety distance by control velocity and acceleration, but ignoring driving physiology and psychology, driving task completion quality, path finding, and how destination impact path selection. For these above reasons, base on real convey data, this study mainly discussed six parts, impact analysis between destination and driving behavior, weaving area impact range, key driving behavior indicator definition, evaluation indicator selection, control strategy analysis, simulation environment build up and evaluation.First, select urban road expressway weaving area as the research object, collect typical weaving area video, analysis statistic charactor of each driving behavior category, digging the reason of special bahaviors such as continuous changing lane form inner lane to outer lane of main carriage vehicle, non merging into main road from ramp, compulsory lane changing of main carriage vehicle, impact of passing capacity and traffic safety. Form a point of view of driving information need and riving task completion quality, duscuss how destination impact driving route choosing, presents a destination oriented method to define weaving area range, provide theory base of information interaction distance.Car following distance, responding time differs as traffic environment, traffic facility, vehicle type, driver character, driving habits changing, especially when huge special driving behavior exsits. To better describ driving behavior, an unmanned Aerial Vehiclem, UVA vedio based indicator definition methd is presented. UVA can capture the whole car following behavior within its shooting range in a high definition manner without disturb driver. Key indicators like car follow distance and responding time is obtained to establish the threshold of car following model suitable for china urban roads.Secondly, based on the analysis of the driving behavior of the weaving area, a 3 phase control strategy is put forward to improve the traffic efficiency consist of destination oriented lane changing, merging into main raod and merging into weaving area. Collect ID, velocity, acceleration, position information, destination of vehicles within control area through interaction communication between vehicle and road infrastructures. Main road vehicle change lanes base on destintion information in upstream phase. On ramp vehicle merge into main road at the beginning of weaving area and with a higher priority, mian raod vehicle can only go rhtough and yield in a platoom way. Vehicles at weaving area should yield to main raod exit flow at the second half of weaving area. The location providing information should let vehicle have sufficient time and distance to take action without a sudden break or other high risk manuvour.Then, evaluation indicators under CVIS are reviewed and analyzed, not only focus on efficiency and safety indicators of the vehicle itselfbut also traffic flow velocity, density, passing time, queue length, delay time, conflicts, the number of dangerous driving behavior, total travel time were analyzed on a perspective of control area. Evaluation index system was build up.Finally, a microsimulation scene was set up by further development of Vissim, indicator defined was put in, strategy developed in the former part was testified and evaluated, and. There is also a further discussion of performance evaluation under different traffic load, different equipment percentage and different comply rate. In the last part, future research direction is prospected. Conclutions of this study have an important realisc meaning to improve urban traffic congestions.