| With the rapid increase in the number of motor vehicles and the intensification of land in China,a large number of large-scale parking lots have been born.The increase in the number of parking spaces can solve the problem of insufficient parking spaces,but it aggravates the influence of dynamic and static traffic,resulting in a series of new "parking difficulties".Among them,there are bottlenecks between entrances and connecting roads,which not only directly affect the difficulty of motor vehicles entering and exiting parking lots,but also lead to slow or congested driving of connecting roads and surrounding road networks,which reduces traffic efficiency.Therefore,this paper studies the dynamic and static traffic congestion and regulation optimization of large parking lots,so as to judge the dynamic and static traffic state and provide quantitative basis for traffic volume control optimization.Firstly,this paper analyzes the dynamic and static traffic characteristics of large parking lots.The arrival and departure characteristics of vehicles in the parking lot are analyzed based on the vehicle entry and exit data of the parking lot,including that the arrival and departure characteristics of vehicles in the same type and different scales parking lots are similar,and the larger the scale of the parking lot,the more concentrated the arrival and departure of vehicles.In addition,the arrival and departure characteristics of vehicles at different entrances and exits in the same parking lot are different.By analyzing the correlation between dynamic and static traffic,it is found that the commercial parking lot is significantly related to the trunk road,which has a high degree of overlap during peak period and the dynamic and static traffic have a severe influence on each other.Therefore,the commercial parking lot is selected as the parking lot type studied in this paper.Traffic characteristic analysis determines the significance of studying the dynamic and static traffic in large parking lots from the data level,and puts forward ideas and directions for dynamic and static traffic optimization.Secondly,the average delay model of dynamic and static traffic vehicles is established,and the method of calibrating model parameters with simulation experimental data is put forward.Under the common forms of dynamic and static traffic steady-state influencing factors,the average delay models of arrival vehicles,departure vehicles and road vehicles in parking lots are established respectively.It is proposed that the model parameters which are difficult to observe and measure directly can be calibrated by simulation experiment data.In order to make the simulation experiment more realistic,the following model parameters are corrected by headway and solved by Particle Swarm Optimization(PSO).In this study,Vissim is redeveloped to realize batch simulation,so as to avoid a lot of repetitive work when calibrating model parameters with simulation experimental data.Then,a method of judging the dynamic and static traffic congestion state and congestion period based on the average vehicle delay is proposed.Congestion judgment is divided into congestion state judgment and congestion period judgment.A congestion state judgment method is proposed to judge whether congestion occurs.The congestion period judgment process is proposed to determine the congestion period: congestion start time,congestion end time and congestion duration.According to the above model and technical method,taking Jingfeng parking lot in Nanjing as a case study,the accuracy of the average vehicle delay model and the feasibility of the congestion judgment method are tested.Finally,the dynamic and static traffic coordination optimization model based on multiple entrances and exits is constructed.The optimization model is based on the average vehicle delay model,with the objective of minimizing the total vehicle delay of all entrances and exits and the roads connecting them,and with the constraints of meeting the arrival and departure demands of parking lots and avoiding the static and dynamic traffic congestion at each entrance and exit.PSO with penalty factor is used to solve the optimization model.The regulation process based on congestion judgment and coordination optimization model is put forward to judge whether congestion occurs,congestion period and calculate the regulation amount after congestion.Taking Jingfeng parking lot as a case study,the practice test is carried out. |
