System Dynamics Model Of Urban Traffic Supply And Demand Disequilibrium In Structure

With the continuous development of economy and the accelerating information construction of traffic system,the complexity and dynamics of urban traffic system are increasing day by day,as well as people's demand.At the same time,the pace of management's development has yet to follow up,the development of science and technology and economic are imbalance in different area,individual differences such as concept and quality,traffic problems become more prone to severe,urban traffic is more important to the economic and social development,as well as the impact.So combing the elements of the urban traffic system,analyzing the contradictory crux and searching for optimal solution seems to be extraordinary necessary and urgent.The mismatching between supply and demand of various kinds of transportation in cities is one of the problems in urban transport.It is the norm that the supply and demand of various kinds of transportation present a state of disequilibrium relative,factor that affect supply and demand of transportation is numerous and dynamically changing.Paper based on the theory of disequilibrium in traffic supply and demand,overcomes the defects of traditional equilibrium theory,cover the shortage of existing research about traffic structure,using the theory of non-equilibrium for the research of urban traffic structure disequilibrium between supply and demand.At the same time,using the method of system dynamics to set up the system dynamics model of urban traffic structure disequilibrium between supply and demand.First of all,traffic supply and demand structure being the basic research object and urban transportation the range of study,paper made a brief introduction of the disequilibrium theory.Then,taking the disequilibrium contradictions of the total supply and demand in traffic structure as a starting point,paper analyzed and discussed the disequilibrium concept of urban traffic structure,the connotation and the related factors of demand and supply.Analysis about supply and demand of urban traffic system structure was conducted.Secondly,basic theories,methods and characteristics of system dynamics were summarized.The applicability of the system dynamics theory in the research of urban traffic structure disequilibrium between supply and demand were analyzed and the basic process to establish the model of urban traffic structure disequilibrium between supply and demand using the method was determined.Based on factor analysis and causality analysis about supply and demand structure of the urban traffic system,the flow diagram was drawn based on computer software VENSIM platform,the system dynamics model of urban traffic structure disequilibrium between supply and demand model was established,and the basic parameters of the model comes from the quantitative analysis equation were determine.Finally,the system dynamic model was tested and simulated.With basic data comes from the statistical yearbook of Guangzhou city,we input the initial value.Getting and comparing the model simulated data with the former to test the validity of the model and predict the tendency of the urban traffic structure disequilibrium between supply and demand.Which proved that the supply and demand of traffic structure remains relatively balance in dynamic.Making study formation mechanism and development trend of urban traffic supply and demand structure system in a systematic and dynamic way.Paper preliminarily expounded the basic structure and action mechanism of the system.Which possesses great theoretic and practical significance in further easing the increasingly prominent contradiction between supply and demand of traffic structure and reasonably guiding the proportion distribution of transportation.