Optimization And Empirical Study Of Urban Traffic Microcirculation Road Network

Traffic microcirculation can manage and divert traffic on the main road network by using resources such as back alleys and branch roads between main roads,which not only effectively reduces the waste of road resources,but also effectively relieves the pressure of traffic congestion.However,the currently implemented traffic microcirculation may interfere with the normal life of residents in the area and affect the fairness of traffic.In order to optimize the traffic microcirculation and reduce the negative impact on the society,this thesis discusses the network optimization model and solution algorithm of the urban traffic microcirculation system according to the traffic flow characteristics of the traffic microcirculation.Then this thesis verifies the theoretical method through empirical research.This thesis takes the branch and secondary roads of two-way two-lane driving in Changsha as an example,and analyzes the traffic flow characteristics of urban traffic microcirculation roads through field investigation.On the basis of sorting out the survey data,this thesis compares the speed of vehicles in the case of meeting and no meeting cars,and compares the samples collected under multiple groups of roads with different widths.Based on cellular automata,this thesis discusses the traffic flow model of the process of car-meeting on urban branches and secondary roads without central separation,and conducts data simulations.The results show that the speed of meeting vehicles on the branch road is related to the width of the road and the speed of the traffic flow on the road itself,and status updates such as two-way traffic flow are determined by the superimposed influence of the own traffic flow in the current direction and the opposite traffic flow.A mathematical model to optimize network design and traffic organization for micro-circulation transportation of urban streets is proposed.With the objectives to minimize the total travel time of vehicles and to minimize the total negative social benefits caused by traffic microcirculation,and considering the constraint of capacity of branch roads and route choices of drivers under a given micro-circulation network,the bilevel programming model for micro-circulation network design and traffic organization is developed,including the selection of branch roads used for micro-circulation transportation,whether it is one-way or two-way traffic on the branch road,and whether it is left-turning forbiddance and goingstraight forbiddance at each entrance lane of the intersection.Finally,an example is given to demonstrate the effectiveness of the model and the algorithm by comparing the data before and after the model optimization.This thesis takes the area composed of Hexi Huanghe Resettlement Community,Jinjiang Resettlement Community,Sunshine 100 Community,Central South University New Campus,Xiaoxiang Middle Road,Second Ring Road,Fengshun Road,and Houhu Road as examples for empirical research.By investigating the current road network situation,traffic status and traffic distribution,this thesis uses optimization model of urban traffic microcirculation organization and solution algorithm to optimize the design of the traffic microcirculation organization in this area,which verifies the feasibility of this study.This thesis provides a reference for the organization of transportation.