Macro Traffic Flow Modeling And Analysis Of Multiple Modes Of Urban Road Network

Urban road traffic is a complex system,including social traffic flow,bus traffic flow and logistics traffic flow.From the perspective of traffic flow system,the basic characteristics are mixed traffic flow.Among them,social traffic flow occupies a large proportion in the traffic flow system,forming the external environment of the public transportation system and the logistics system.At present,most of the related research focuses on the interaction between social vehicles and public transportation vehicles.In this paper,the three-dimensional MFD(Three-dimensional Macroscopic Fundamental Diagram)model of urban road network is used to model and analyze the macro traffic flow of various modes of transportation in urban road network.The theory is based on the extension of MFD,which can reflect the interaction between various modes of transportation in urban road network and can express the macro traffic flow in urban road network.Based on the moving trajectory data processing of various vehicles in the second to third ring areas of southeast Beijing,combined with the threedimensional MFD theory of urban road network,the existence of three-dimensional MFD in the regional road network is verified,and the logistics vehicles are introduced into the model as a key element for research and analysis.At the same time,this paper analyzes the influencing factors of the three-dimensional MFD of the urban road network by combining the simulation data,and puts forward the traffic control method to study the control of various traffic modes in the region.The main research work of this paper is as follows :(1)Empirical analysis of three-dimensional MFD of urban road network : The moving trajectory data of various vehicles in the experimental area(including travel time,origin,destination and route information)are processed into traffic flow data such as traffic flow,speed and density,and then the three-dimensional MFD of urban road network is established.This paper analyzes the relationship between different parameters in the model,and studies the traffic congestion and traffic flow changes under different conditions,and makes an empirical analysis of the three-dimensional MFD of the urban road network in the experimental area.(2)Based on the actual traffic flow data and map data,a simulation model is built to analyze the influence of public transportation system and logistics vehicle system on the three-dimensional MFD of urban road network.Therefore,this study analyzes the influencing factors such as site distribution,line distribution,bus lane layout in the bus system,as well as the distribution of cargo distribution points and cargo distribution routes in the logistics vehicle system in combination with simulation software.(3)Design of three-dimensional MFD control strategy based on urban road network : Based on the analysis of the influencing factors of three-dimensional MFD of urban road network,the simulation model is used to carry out macro-control and micro-control of various travel modes in urban road network.The three-dimensional MFD of urban road network is used to establish the vehicle input model of controlled area and design the feedback control law of controlled boundary traffic flow input.The effectiveness of the proposed control strategy is verified by simulation experiments.The simulation model is built by using the vehicle routing problem with time window(VPRTW)problem combined with the real data of logistics vehicles,and the logistics vehicle path in the experimental road network is optimized and allocated.The path optimization efficiency is verified by collecting the traffic flow parameters of logistics vehicles before and after optimization.