Research On The Optimization Of The Last Train Timetable Of Urban Rail Transit

As the scale of urban rail transit networks continues to expand and the complexity of the network continues to increase,the synchronous optimization of the last train timetable becomes more and more important,and it has become an inevitable choice for networked operations.Reasonable design of the last train timetable can synchronize the transfer time of the last bus of different lines to ensure that more passengers arrive at the destination,which is particularly important for network accessibility and overall service quality.Firstly,starting from the passenger flow of the entire network,stations and transfer stations,this paper discusses the distribution and path selection characteristics of passenger travel during the last train time,and analyzes the influencing factors such as operation management and design during the last train time.The last train driving organization plan provides data and management basis.Afterwards,the basic conditions and mechanism of the connection coordination of each transfer direction in the last train network were analyzed using a mathematical model,and the relationship between a single transfer station,multiple transfer stations,and the coordination of the line network was described.On this basis,the connotation of the transfer coordination and the existing optimization methods for the connection of the last train are summarized.It is pointed out that the optimization method based on passenger OD reach can be considered from the passenger’s complete travel path and the passenger’s multi-path selection,which is more in line with the goal of the last train schedule,to provide a theoretical basis for the optimization model of the last schedule of urban rail transit.Then,on the basis of considering the transfer penalties and travel time costs in passenger travel costs,the generalized cost of travel on the last train and the criteria for judging the reachability of travel were proposed,and a method for coordinated optimization of the last train timetable was proposed with the goal of the proportion of passengers in the network,and based on the K-shortest algorithm,a calculation model for the reachability of the last train and a genetic algorithm designed for the characteristics of the target model are proposed for solving.Finally,taking the Xi’an rail transit network as an example,the effectiveness of the OD reachability calculation method and genetic algorithm in practical applications is analyzed,and the OD reachability model and the transferability reachability model in the actual network are further verified difference.(1)In terms of algorithm,the calculation method and genetic algorithm of the last train based on K-shortest can effectively obtain the optimal solution of the model,and the model can obtain the optimal solution in 35 minutes,which can meet the actual operational needs.(2)The model can effectively optimize the reachable passenger ratio of the last train.The model based on the maximum OD reachability can increase the number of last passengers arriving at the destination by 12.03% and the number of reachable ODs by 4.52%.(3)The optimization effect of the OD accessibility model is better than the transfer accessibility model.For the Xi’an network,its OD reachability model can reach 12.03% of the number of passengers,which is higher than the transfer connection model of 9.61%.In summary,the OD reachability optimization strategy can further improve network reachability on the basis of transfer connection optimization.In a large-scale network,passengers have rich choices of travel routes and more travel transfers.The OD accessibility model should be adopted to ensure that passengers reach their destinations to the greatest extent,thereby improving the coordination of the last train operation of the urban rail network,the maximization of social and economic benefits of transportation networks has important theoretical and practical significance,and more has good application prospects and value.