Study On Traffic Flow Characteristics Of Urban Road Network Based On Multiplex Networks Structure

With the rapid development of economy and the continuous advancement of urbanization,the number of motor vehicles,and the load of urban roads keep increasing,leading to more and more severe traffic congestion problems.How to reasonably plan traffic resources and alleviate urban traffic congestion has become an urgent problem nowadays.The study of traffic flow model can provide a theoretical basis for the rational planning of roads and the control and management of traffic systems,and help to alleviate and suppress traffic congestion.In the research of microscopic traffic flow model,TASEP model and NaSch model are two common models.The TASEP model is relatively simple which can characterize the movement of vehicles in general,while the NaSch model takes into account some more detailed elements,which can simulate the acceleration and deceleration of the vehicle.At present,most of the microscopic traffic flow model research focuses on the one-dimensional structure and simple network,without considering the multi-layer nature of the urban road network.This paper considers the TASEP model based on multiplex networks and the Manhattan-like urban traffic model with long-range links,to study how the multilayer network structure may influence the traffic flow.The main work of this paper is as follows:1.Considering that most of the previous studies on TASEP model focus on one dimention chain or simple networks,the TASEP model on multiplex networks is proposed.This model constructs the multi-layer network by setting different "speeds",i.e.hopping rates,for different types of links.First,the theoretical solution of the current-density relationship is obtained through the mean-field theory.The theoretical results and the simulation results are in good agreement.Then,by extensive simulations,the influence of the multi-layered network on the current-density relationship is studied.It is found that increasing the speed of some road segments may cause the global traffic condition to deteriorate.Finally,by dividing the upstream and downstream of the high-speed segments into four categories,the density distribution of the segments is analyzed in detail to explain the cause of this phenomenon.2.Considering that most of the previous studies on Nasch model focus on one dimention chain or simple networks,the Manhattan-like urban traffic model with long-range links is proposed.The model sets different "speeds" for long-range links and Manhattan-like urban networks,as well the traffic lights for intersections and OD attributes for vehicles(vehicles travel along the shortest path from the original place to the destination).Then,the effects of multilayer network on current-density,velocity-density,congestion center and congestion degree are studied through extensive simulations.It is found that adding a small number of long-range links randomly can degrade the overall performance of the road network.Finally,the cause of this phenomenon is analyzed by analyzing density distribution of segments under different number of long-range links and different states.3.The traffic flow simulation system is designed and implemented based on the TASEP model on multiplex networks and the Manhattan-like urban network model with long-range links.The system input parameters such as density into the model to obtain traffic flow characteristics such as current-density relation and density distribution of the network.