Study On The Combined Operation Of Express/Local Train For Urban Rail Transit

With the development of urban rail transit network and the expansion of city scale,passengers’ travel distance is getting longer and longer. Traditional way of stop schedule plan gradually cannot meet the demand of passengers diversified travel, the appearance of express/local train combination operation, makes it possible to shorten travel time of the long distance passengers and to reduce operation costs of operational enterprise. But the implementation of the express/local train mode has its specific passenger flow condition and line condition, whether to choose it needs analysis in detail combined with the circumstances of passenger flow.On the base of summarizing the research about the combined operation of the express/local train at home and abroad,the paper studies running mode of express/local train It quantitatively analyze the train marshalling, the train route plan and the express/local train scheme under the multiplex modes. After determining the train marshalling and the train road, it establishes express stop scheme optimization model from the two angles of the passengers and the enterprise on the base of considering the factors of the station classification. Then it designs genetic algorithm to solve the model according to the model’s feature. Finally, it makes Chengdu metro line 2 as an example to verify how stop scheme optimization model works. Paper’s concrete research contents are as follows:1. It illustrates the conception about combined operation of express/local train, and analyze its advantages and disadvantages from two angles of passengers and operation enterprises. It classified the express/local train modes respectively from two aspects of operation speed and operation line, and then explains the characteristics of each classification mode. It analyzes the effect of express/local train making on line carrying capacity from two angles of whether to implement overtaking. Analyzing the organization factors when implementing overtaking, finally it is concluded line carrying capacity of express/local train system.2. It quantitatively analyze the time distribution and space distribution features of urban rail transit passenger flow and the applicable conditions of express/local train. It studies kinds of station layout pattern features to complete train overtaking and their advantages and disadvantages. The patterns of turn-back station’s turn lines are also discussed. Finally it is concluded that appropriate line features suitable for implementing express/local train.3. It analyzes the way to determine vehicle type, train marshalling and train routing, and qualitatively analyze the express/local train in multiplexing mode, then optimizes the express/local train stop schedule plan. On the premise of overall consideration about passenger flow characteristics at stations and station’s status in the road network and in society, it uses affinity propagation cluster to classify stations. On the base of classified stations, it establishes express stop scheme optimization model from the two angles of the passengers and the enterprise. Then it uses the ideal point method to change the double objective model to single objective model,and design genetic algorithm to solve the model by its feature. Finally, by taking Chengdu metro line 2 as an example, it analyzes whether the express stop scheme optimization model is scientific.