Research On Flow Assignment Of Urban Rail Transit

With the sustainable development of the domestic economy as well as the accelerated process of urbanization and motorization, traffic problem has been the "bottleneck" of the cities' sustainable development. Giving priority to the mass transit is the important measure to solve the problem, and developing the urban rail transit is the important aspect. Urban rail transit is an effective mean of transportation to ease the traffic pressure. It is used in more and more large and medium-sized cities because of its large capacity, rapidity, punctuality, less pollution.With the construction of urban rail transit, the network forms grandually. The operatation management will also take a grandual transit from one-way operatation to network-based operatation. After the formation of the traffic network, the passenger flow of one-way operation will show new characteristics with the increase of the rail lines and bring the corresponding changes of the net passenger flow distribution accordingly. Especially under the conditions of one-ticket transfer, the passengers' trip route will take on more obvious diversity.First of all, the paper analyses the trend of urban rail transit overseas and the time-space distribution characteristics, especially the difference between one-way operatation and network-based operatation.Then, anaylising the factors influencing passengers' choice, considering congest, passengers' delay caused by the crowds and the queuing time whiling transferring to another rail, we get the more reasonable path cost function. And then we distribute the passenger flow using logit model.Finally, the paper analyses the trend of passenger flow growth of Beijing Urban Rail Transit. Then it calculates the assignment propotion and analyses the influcing factors. And we analyses the influence of path fees to the assignment propotion. At last, we analyse the sensitivity of valid path threshold, transfer sensitivity, passengers' familiarity with the network.