Optimization Of Urban Public Transport Network Based On Accessibility

With the accelerating process of urbanization in China,the urban traffic problem is becoming more and more serious.For the highly intensive cities,motor-oriented traffic planning is not a good way to improve the accessibility of urban transport.Vigorously developing public transport is the main way to alleviate urban traffic problems,and bus accessibility is the ultimate goal of its development.In order to promote the development of public transportation,this thesis studies the optimization method of urban public transit network from the perspective of accessibility.First of all,the basic meaning and influencing factors of bus reachability are analyzed,which is defined as " The opportunity size of travelers in the travel area use the public transport from the starting point of the trip to reach the end ".Analyzing the influence factors of the accessibility of the bus from he traffic facility condition,the land use,the traveler attribute and so on.The accessibility of the bus is quantitatively analyzed from the internal reachability of the site and the accessibility of the bus network.The former is measured by the walking index in the traveling area.The latter is measured by the generalized cost of the bus trip.And on the basis of the utility model,the two kinds of bus reachability measure combination,put forward more explanatory and comprehensive quantitative method.Then,the thesis analyzes the guiding role of the site in the process of urban development,taking into account the accessibility of the bus station,the amount of travel and the network topology indicators to classify the bus stations,and divide the bus network into express line layer,general line layer and feeder layer,and the characteristics of each layer of network and the relationship between each other are analyzed.Different optimization models are proposed for each layer of bus network:the express line layer is the objective function with the maximum passenger flow density,the general line layer is the objective function with the minimal passenger travel impedance,and the feeder layer is the objective function with the maximum network coverage,And the range of the constraint conditions of each layer model is studied respectively.Finally,the ant colony algorithm is used to optimize the layout of the public transport network.With the help of Matlab software programming,the optimization method and algorithm are verified by an example,which proves that it has certain feasibility and rationality.In this thesis,the optimization of public transport network for the purpose of accessibility is transformed from site-oriented bus network optimization,and the bus accessibility is the ultimate goal of public transportation network optimization.Site classification and bus network stratification optimization method are proposed,The problem of complex multi-objective optimization is simple and has some theoretical and practical significance.