The Research On Road Network Capacity And Its Application Under The Evolution Of Urban Road Traffic System

A large number of cars have emerged in the city,a large number of people have gathered,the total number of residents has been increased substantially,and the proportion of motor vehicles traveled has been risen rapidly,making urban traffic problems more complicated and contradictory.Urban road traffic is closely related to residents' travels.If the urban road traffic problem is not controlled,the urban road traffic system will be developed in a chaotic and disorderly direction,eventually leading to the collapse of the system.Urban road network is an important part of urban road transportation system.The rationality of its scale is the basis for formulating scientific and effective traffic management policies and giving full play to the functions of road network.Road network capacity is one of the important indicators to reflect its rationality.Accurately grasping the capacity of road network is conducive to the effective management of urban traffic.Complexity science has a wide range of research and application in road network structure,but little research has been done on road network capacity.This thesis takes urban road network as the researching object,uses self-organization theory to study the evolution process of urban road transportation system and studies the road network capacity in the evolution process,thus enriching the application of complexity science in transportation field.The specific research contents are as follows.First of all,this thesis studies the evolution process of urban road traffic system from the theory of self-organization.Features such as open systems,away from equilibrium,nonlinear interactions,and ubiquity of fluctuations are necessary conditions for system evolution.The system evolution mechanism includes self-organization and composite evolution mechanism.The system self-organization evolution model and the supply-demand co-evolution model were established respectively.For the urban road traffic system evolution model,the three parameters of road network density,road area rate and road network capacity were used to explain the rationality of supply,and then multiple regression analysis method was used to predict the future traffic volume of the system evolution.According to the urban road supply and demand matching index,the evolution model of urban road transportation system was obtained:supply and demand follow-up type-car transportation development mode,supply and demand advanced type-public transportation development mode,supply and demand guidance type-mixed traffic development mode.Then,a bi-level programming model as a road network capacity was constructed to solve model.The internal and external influences of the urban road traffic system,the random path selection behavior of the traffic individual,the saturation of the road segment and other influencing factors were considered,and then the calculation model of the double-layer planning of the road network capacity was discussed,and the model was revised and the solution steps were given.Finally,Changsha was selected an empirical object to build a model,which summarizes the development of the road network in Changsha,and generalizes the problems of the road network at the macro,meso and micro levels.At the same time,the slow relaxation variables of urban road traffic system in Changsha City include urban population,vehicle ownership,road length and road area were determined.The supply and demand status of the system under different organizational forces and the corresponding traffic were explained by MATLAB software simulation.Development model.From the statistical analysis of road network density and road area ratio,it had been found that these two indicators in Changsha City have not reached a reasonable value,and multiple linear regression models were used to predict the traffic demand in Changsha City from 2018 to 2022.The TransCAD software was combined with the bi-level programming model to calculate the road network capacity value of Changsha City.The value was applied to the calculation of the urban road supply and demand matching index.The development mode of the road traffic system in Changsha City from 2018 to 2022 was from the mixed traffic mode to Car traffic mode.A comprehensive analysis of the systematic evolution of empirical research and the rationality of supply and demand,and propose measures and recommendations to promote the orderly development of urban road transportation system in Changsha.