Traffic Assignment Problem Of Urban Railway Transit Based On Seamless Transfer

With the expanding scale of urban railway transit construction, network operation has become an inevitable trend. Under the network operation mode, passengers have realized seamless transfer in the urban railway transit. Passengers can travel through ticketing once. However, under the condition of seamless transfer, path flow and transfer flow is difficult to determine and statistics because the route choice behavior of passengers is diversified. In this case, study on the route choice behavior of passengers in the network and determine traffic assignment of each path, will be of great significance to organize transport work efficiently, construct urban rail traffic ticket income distribution system and predict the impact of new lines of existing railway passenger flow.Treat the city rail transit network as the research object, around passenger flow assignment problem of urban railway transit based on seamless transfer, the main research work in this paper as follows:(1) Study on the route choice behavior of passengers in urban railway transit network based on behavior theory, consider that the behavior is a random selection process and consistent with the discrete choice theory. Summarized the influence factors of passengers in the route choice behavior from two aspects:passengers attribute factors and external environmentalfactors; proposes using the chi square test or t test to analysis the significant of factors and eliminates the factors with little influence. Using the investigation method which combines the RP with SP, design questionnaire for the research to urban railway transit passenger route choice behavior.(2) Study on the composition and representation of urban railway transit network and summarizes the commonly used search method of effective path in the traffic network, and uses the breadth-first search algorithm which fits the urban rail transit network well.(3) Establish the generalized cost function of passenger travel based on the seamless transfer mode of urban railway transit. Divide congestion cost into dynamic congestion cost and static congestion cost according to the characteristics of passengers in different period. Analyzes the limitations of route choice Multinomial Logit Model, consider that the results of Multinomial Logit Model will be inconsistent with the actual situation when the network scale is large. Establishes Nested Logit Model for the traffic assignment problem of urban railway transit, which can adapt to large-scale network well. Design successive average method of urban railway transit network considering the crowded degree with the change of passenger flow. In addition, introduces the calculation method of OD matrix between lines and stations.(4) Take the Chengdu subway network as an example to construct the network diagram. Calculate the passenger flow assignment proportion of the long, medium and short distance OD in the peak hours of peace-peak hours of Chengdu subway line based on Nested Logit Model of route choice. Analyze the sensitivity of the coefficient in the model, which can provide a reference for the selection of parameters in the practical application.