Train Planning Optimization For Through Operation Between Subway And Suburban Railway

Subway and suburban railway play important roles in passenger transport system. Subway mainly serves for short distance passengers, while suburban railway mainly serves for long distance commuters between city center and suburb. Suburban railways generally stop beyond the city, which result in transferring between subway and suburban railway for commuters. Enormous transfer passengers in peak hours make great operational risk, and it also reduce the service level.Through operation between subway and suburban railway can reduce transfer, which is an important measure to reduce risk and improve service level. Train planning is one of the basic technical issues for train operation organization. It is the guidance document for coordinating among companies, ensuring safety train operation and improving service quality. Therefore, it is significantly important to optimize train planning for through operation between subway and suburban railway.Taking the through operation between subway and suburban railway as research background, this paper firstly studies the necessity and feasibility of through operation. Then, optimization models for train planning under vehicle rental, line rental and mutual through operation mode are proposed. Furthermore, the applicability of the three operation modes’ train planning is discussed. Finally, stopping pattern optimization model for through operation is proposed. The main contents and conclusions of the dissertation are as follows.(1) Based on the saving time benefits of passengers and increased investment cost of operating companies, the method to judge the necessity of through operation is proposed, and the minimum through passengers for through operation is calculated. Then, the minimum through passengers in different transfer time, time value of passengers and investment cost are analyzed. The results indicate that the more transfer passengers are, the longer transfer time is, the more necessity for through operation. What’s more, it is necessary to take through operation into consideration in the line planning and design stage.(2) The feasibility of through operation is studied based on line capacity. By considering the difference of tracking interval time between different trains and the same trains, deduction coefficient method and periodic train analysis method are used to calculate the maximum number of trains operating on shared-track section. Then, the effect of through operation train on line capacity is analyzed. The connection between line capacity and feasibility of through operation is also discussed. The results show that the same operation speed is preferred for the trains on shared-track section. The smaller the headway of the initial train operation is, the fewer through trains are allowed. The numerical example indicates that when the average headway of subway is less than 125s, through operation is infeasible.(3) Based on the characteristics and differences of vehicle rental, line rental and mutual through operation mode, the train planning optimizing method is studied. Optimization models are presented to determine the shared-track section and train frequency for three through operation modes, respectively. Take maximum benefit of suburban railway and passengers as optimization objective, a multi-objective model is establish under vehicle rental mode, and an algorithm combined with algebraic weighted method and genetic algorithm is designed to solve the problem. Take maximum benefit of subway and passengers as optimization objective, a multi-objective model is established under line rental mode. Taking maximum benefit of passengers as optimization objective, a optimization model is presented under mutual mode.The results show that subway and suburban railway companies have large space to negotiation in vehicle rent without affecting train operation plan under vehicle rental mode. If the operation expense is high for company, high government subsidies are needed to safeguard operation under line rental mode. Under mutual mode, the larger the gap between the station distance of subway and suburban railway is, the smaller the shared-track distance is. The numerical example indicates that the average suburban railway station distance should not exceed 6 km.(4) With comprehensive consideration of the benefit of operating companies and passengers, the operation effects of optimal train planning with different distribution of through passenger flow are analyzed under vehicle rental, line rental and mutual mode. Under vehicle rental and line rental mode, the operation effect is analyzed with three kinds of passenger flow distribution at suburban railway stations, which is uniform distribution, diminishing far distribution and bimodal distribution. Under mutual mode, the operation effect is analyzed with nine kinds of passenger flow distribution, which is uniform distribution, diminishing far distribution and bimodal distribution at suburban railway stations, and uniform distribution, diminishing far distribution and similar normal distribution at subway stations. The results show that if through passenger flow near transfer station is large on subway line, vehicle rental and mutual mode are suitable for the situation. If through passenger flow near transfer station is large on both lines, mutual mode is suitable. If through passenger flow far away from transfer station is large on subway lines with logging ticket price, line rental mode is more suitable.(5) Skip-stop pattern and train frequency is studied when the through trains operating combine with all-stop operation and skip-stop operation. Optimization model, with the objective to maximize total through passenger saving time, for through train stop pattern is proposed by considering the line condition of subway and suburban railway. Lagrange relaxation algorithm is designed to solve this problem. The numerical example indicates that operation mode combined with all-stop and skip-stop operation saves great travel time as to all-stop operation, the total saved time for through passengers is 267.7 hours, and the total increased time for through passengers that are out of service for skip-stop operation is 62.6 hours.