The Congestion Propagation Rules And Influence In Urban Rail Transit

There is an increasing pressure on urban transport with urbanization. Developing public transport in priority has become an important policy to deal with the traffic problems in many cities. Urban rail transport therefore develops rapidly as an important part of public transportation. With an increasing scale of urban rail transit network, a growing number of passengers choose to travel by urban rail transport system, which may result in overload of the train and difficulties for passengers to get during peak periods. Therefore, the study of urban rail traffic congestion has an important practical significance.Urban rail traffic congestion has been investigated in following aspects:(1)The basic features of urban rail transport network were analyzed and calculated using the Complex Network Theory. The results show that there are a small-world effect and a scale-free property in the urban rail transport system. An urban rail traffic congestion propagation model was established based on Complex Network Propagation Dynamics Theory and the classical model of network propagation. The urban rail transport network of Beijing was analyzed and the corresponding congestion propagation rules were obtained.(2)Various cost factors were analyzed and quantified considering the choice of travel paths of passengers. A comprehensive path cost function was established corresponding to the real situation. An effective path searching algorithm appropriate for rail transport system was set in Dijkstra Shortest Path Algorithms, basing on the principle of Border Erase Method. An equilibrium assignment model considering congestion effects was then established based on the Logit model. The model was solved using MSA and MSWA algorithms.(3)The topology of Beijing rail transport network was built using Graph Theory and calculated using SUE Model considering congestion effects. Path selection and flow distribution were achieved with different passengers’familiarities to the rail network, common and peak periods and limiting methods, separately. Results were verified with real situation. The effect of new line on existing network was investigated by comparing the passenger flow before and after the opening of Line6first phase and Line10second phase. The effect of road suite running method using in Line6on easing congestion was analyzed.