Multi-Modal Urban Mixed Traffic Network Assignment Based On Transfer

With the development of city economy, comprehensive transportation which includes car, bus, rail transportation is being improved. Travelers may have a single mode choice even combined-mode choice based on different demands and traffic pattern itself. Then inevitably involves the transfer problem. The cooperation of each traffic pattern is more advantageous to improve the transportation efficiency of the whole transportation system. This paper is to study the city consider multi-modal transfer under the condition of traffic network assignment problem.This paper firstly introduced the concept of hyper-network to describe the multimodal of urban traffic network, for the following travelers’traffic mode and travel route choice behaviours according to the network structure characteristics. At the same time, using the Dijkstra algorithm to search the shortest paths, simultaneously compared the advantages and disadvantages of different effective paths to redefined it based on graph theory. Then the three conditions including the number of transfer is given according to the actual situation. Based on the graph traversal algorithm to search effective paths can greatly improve the computational efficiency.Then the additive generalized cost function is divided into account transfer generalized cost function include spenalty, link generalized cost function includes time, money and etc. Combined with the expansion of the network for virtual transfer points and the construction principles, this paper established the traffic road impedance function model. Road impedance research includes:car sub network connection, bus sub network connection and multimodal transfer connection.Finally, the path selection and mode selection based on the elasticity of demand for travel of disaggregate mode description. Thinking about the IIA characteristic of Logit model, choose the three layers of nested user that includes rout choice, transfer nodes choice and traffic patterns choice. This model includes the stochastic demands of multi-modal transfer under the urban traffic network for equilibrium assignment. Then, numerical examples are given and the use of the improved MSA algorithm is used to solve the problem.