Research On Carrying Capacity Of Road Network Based On Multi-direction Congested Node

Urban road network is a collection of intersections and road sections.Because of the asymmetry of traffic information,the varieties of traveler trip decision and the other factors,the road network system becomes a complex system with random changes in real time.The carrying capacity of road network represents the limit capacity of traffic flow,providing a theoretical basis for the city traffic demand management,and is of great significance to guide construction of city traffic facilities,traffic organization and control,the direction of the development of city transportation.In the urban road network,nodes often become the source of congestion,which restricts the capacity of regional road network.In order to solve this problem,this paper establishes the road network structure based on multi-direction congestion of the node.On the basis of taking into account the characteristics of traveler,the traffic flow loading mechanism is established to solve the carrying capacity of road network based on the traffic assignment simulation method.Firstly,thus paper analyses the impedance model and node structure.Based on this,a super-node model based on multi – direction congestion of the node is established.In order to reduce the redundancy of storage,the model considers recording the flow and impedance of the node in the way of updating the matrix.When the flow reaches the upper limit of capacity,the turn becomes invalid,losing the connectivity.On the basis of the node model,the paper improves the representation of the path and the process of redistribution after the traffic jam From the path to the road network,this paper puts forward the adjacency list method to store up topological structure of the road network,and the spread process of road network congestion is analyzed with the node as the source.Secondly,on the basis of the traditional path selection,the paper makes a comprehensive consideration of the traveler’s rational and perceptual characteristics.Taking the prior information and real time information as the stimulus,the attitudes towards current and future traffic conditions as the decision basis,a route choice model is established.Based on the route choice,the traffic loading mechanism is developed.Through the comparative analysis,the road network traffic loading mechanism in this paper is more in line with the actual traffic flow and the formation of urban traffic peak.Finally,according to the above theoretical research results,the corresponding division of the flow rate and saturation criteria are established.On the basis of the traditional traffic distribution simulation method,the paper puts forward second-loading,and designs an algorithm to calculate the carrying capacity of road network.At the end of the fourth chapter,a numerical example is given to demonstrate the calculation process of the road network carrying capacity.The results show that the method in the paper is more practical and the results are more detailed and effective.This paper aims at the research and analysis of urban traffic network flow,and establishes the road network structure model based on multi-congestion of the node,improve the route choice and the loading mechanism of the road network traffic.On this basis,the carrying capacity of the road network is solved,which provides scientific and effective theoretical basis for urban traffic management...