The Research On The Diffusion Of Recurrent Congestion On Urban Road And Forecasting Method

Transportation came from the social production and living activities,greatly related to human behavior.With the invention and development of automobiles,great changes occurred within transportation system,which heavily propelled human progress. In modern society,the increased use of automobiles becomes a headache for the consequent traffic congestion. The study on the diffusion and models of traffic congestion has important significations. The research not only provides theory basis and methodology for traffic congestion counter-measures,but also enhances the efficiency of congestion dispersal strategies,so it can save the valuable time of traffic congestion dispersal, improves the utilization efficiency of traffic management resources, induces the adverse influences of traffic congestion.This dissertation based on the sub-item"The Study on Theory and Methodology of Prediction and Prevention of Traffic Congestion",which is an element of National Science Foundation Item"The Study on Key Theory of Urban Road Network Dynamic Traffic Management and Control and Simulation Technology"(No.500338030).The purpose of this dissertation is to construct congestion estimation models base on the time and space. This dissertation proposes the method for identifying the diffusion of congestion and builds new estimation models by using queuing theory, forecasting model,statistics analysis methods and microscopic simulation.This dissertation first puts forward the necessity and feasibility of the research based on actually status,obtained the different characteristics of recurrent congestion and non-recurrent congestion. Then confirm the substance of this thesis is the recurrent congestion on the urban road. The major content of the dissertation were classify the urban road to two parts which is the single road and the road network. To the single road,this dissertation studied the congestion estimation models which based on fixed detectors and floating cars,then constructed the combination forecasting method to forecast the traffic flow parameter. Use the queue length and the congestion duration time to describe the microscopic congestion diffuse extension. To the road network,classify the traffic congestion into primary congestion and secondary congestion depending on the appeared time of the congestion. In this dissertation,use the crossing index and the section index of congestion measure to estimate the congestion diffuse in road network. Finally,use the simulation data to analyzed the precision of these models and the index of describing congestion diffusion.Major research content of each chapter as following:Fist Chapter:Introduction. First,the chapter illustrates the foundation of subject and the background of the thesis which is researched significance and necessity. Then brief discussed the domestic and international present situation and existent problems on the congestion diffuse. Finally, bring forward the purpose and meaning of this thesis,which establish foundation and show clearly direction for the research of later chapter.Second chapter:The foundation and situation of research. This chapter firstly introduces the basic principle and basic concept about the traffic congestion. Then discuss the situation of the congestion diffusion particularly and analyze the applicably condition of the different model. Finally,confirm the major content of this thesis.3th chapter:The research on congestion diffusion extension of the single road. First,introduce the different type detectors on urban street and the types of traffic flow parameter obtain from it. Then construct different congestion index base on the different parameter .and analysis the relationship between the congestion index and classify it. In this chapter,also construct the combination forecasting method and use the optimal weighting method to define the coefficient. Finally,use the simulation data to validate the efficiency of the model.4th chapter:The research on the congestion diffusion extension of the primary congestion. In this chapter,construct the primary congestion diffuse extension models which base on the different measure of fixed detectors. Then use simulation data to validate the consistency between the crossing index and the section index.5th chapter:Conclusion and prospect. This chapter has the conclusion of the major accomplishment and put forward the problem to be studied further.