Optimizing Last Train Timetable Synchronization For Urban Railway Transits

Nowadays,more and more cities enter in the era of rail transit networks.How to use a good operation strategy to maximize the performance of urban rail transit network,and to improve the standard of service and service quality has become the focus of the study.The last train timetable optimization problem an important part of these strategies.A good schedule of last train should be able to connect the key transfer direction,improve the accessibility of the network and connect more passengers.This paper aims to solve this problem.The specific researches are as follows.Firstly,there are two improvements to the study of the existing timetable optimization of the last train.The first is to enlarge the number of connecting passengers as much as possible under the premise of restricting the specific transfer direction(such as the direction of the city.The second is to connect a pair of transfer direction by extending the dwell time.Secondly,the transfer direction and the transfer time were analyzed.Through the derivation,the formulas of the transfer direction of the intersection lines in the transfer station are given.Combined with the tail effect,the walking time calculation method is given.Based on the analysis of the passenger characteristics of the last train,the spatial distribution of the transfer direction is summarized.I found that during the last train time passengers are more concerned about the transit is successful or not.And I analyzed the problems and convergence effect of the timetable of the last train in Beijing.Thirdly,I have used the mathematical methods to describe the transfer process of last train.Based on the two opinions.I built up a model of last train timetable optimization with the considering of specific transfer direction.Another model is with the considering of two-way transfer.And then,I used the genetic algorithm to solve these models.Finally,I designed an example of a small rail transit network.The applicability and validity of the two time table optimization models are verified under the simulated network.The results show that compared with the original schedules,the last train timetable model which considered the specific transfer direction has added one transfer direction.And the specific transfer direction is all connected successfully.The number of transfer passenger who were successfully transfer to another train has 225 more than before.Another last train timetable model which considered the two-way transfer has added two transfer directions.And its connecting passengers number is 288 more than before.The two timetables which have been optimized didn't have "JUST MISS" effect.So the applicability and validity of two models are verified.