The Optimization Of Transit Network Systems

With rapid development of economy and the accelerating process of urban modernization in our country,urban traffic congestion has being increasing serious,the traffic condition continues to deteriorate which affect passengers' daily life and the development of cities' economy.The basic reason for this problem is due to the development of the cities' public transport system is not perfect enough.In order to reduce the congestion and alleviate traffic pressure,the public transport system is must be optimized to improve the overall efficiency of the public transport system.Only in this way can we attractive more passengers to public transport system.Based on seniors' research,in this dissertation the public transport system optimization mainly from two aspects:the path optimization and flow assignment of public transport network.The main contents of this dissertation as follows:In the first part,according to the time-varying characteristic of the bus running time,the mathematical programming model of time-varying transit network is first given,then two-stage algorithm is used to solve the mathematical programming model,using the reduction algorithm to get the minimum transfer times routes.On this basis,the time-varying Dijkstra algorithm is given to get the shortest path.Finally an example is given to prove the effectiveness for the proposed algorithm in solving the optimal route choice problem of time-varying transit network.In the second part,based on stochastic equilibrium assignment,the influence with subway and the number of transfer and the congestion to assignment is considered,passenger travel cost including travel time,waiting time,transfer time,congestion delay time is given.Under the condition of the capacity limitation,the subway environment with stochastic equilibrium assignment model is established,and then Bell iterative algorithm is used to solve the model.Finally using an example to illustrate the practicability of the model.