Working out an incomplete cyclic train timetable for high-speed railways by computer

Period. Polytech. Transp. Eng.

et al. 2020

With the aim of supporting future traffic needs, an account of how to reconstruct an existing cyclic timetable by inserting additional train services will be given in this paper. The Timetable-based Extra Train Services Inserting (TETSI) problem is regarded as an integration of railway scheduling and rescheduling problem. The TETSI problem therefore is considered involving many constraints, such as flexible running times, dwell times, headway and time windows. Characterized based on an event-activity graph, a general Mixed Integer Program model for this problem is formulated. In addition, several extensions to the general model are further proposed. The real-world constraints that concerning the acceleration and deceleration times, priority for overtaking, allowed adjustments, periodic structure and frequency of services are incorporated into the general model. From numerical investigations using data from Shanghai-Hangzhou High-Speed Railway in China, the proposed framework and associated techniques are tested and shown to be effective.

Section: Constraintsmentioning

confidence: 99%

Inserting Extra Train Services on High-Speed Railway

Period. Polytech. Transp. Eng.

et al. 2020

“…In fact, the above mixed operation policy with various types of passenger trains in China HSR calls for more sophisticated timetable planning methodologies and techniques. Moreover, a hybrid timetable concept named ''cyclic + noncyclic'' timetable is possible, with a cyclic core timetable, in which non-cyclic trains such as low frequency and interline trains are inserted as extra trains (Xie and Nie (2009) and Yang et al (2010)). This generic timetable consists of both cyclic trains and non-cyclic trains and be scheduled in tactical planning.…”

Section: Introductionmentioning

confidence: 99%

Integration of Train-Set Circulation and Adding Train Paths Problem Based on an Existing Cyclic Timetable

et al. 2020

IEEE Access

With the aim of supporting the process of scheduling a hybrid cyclic timetable and adapting traffic needs, this paper is concerned with inserting additional train paths problem for tactical and short-term planning applications with multiple objectives. Focusing on an existing cyclic timetable on a high-speed passenger rail line, the problem is to minimize both the total adjustments for initial trains and the number of required train-sets. The timetable scheduling, train-set planning and rescheduling are three complex optimization problems respectively and usually solved in a sequential manner. In this paper, these phases are integrated in a mixed integer programming model, and the multi-objective adding train paths (ATP) model is proposed, which decides simultaneously initial trains' modifications, additional trains' schedules and train-set circulation. The tolerance of disruption for initial trains including allowed adjustment and periodic structure is taken into account in light of the practical concerns. The difficulty of this integrated problem is that train-sets circulation is usually determined after all of the train lines and timetable have been fixed. However, in the adding train paths problem, the additional trains do not exist in the initial timetable. In order to solve the problem in a reasonable time, a relaxation approach to the adding paths problem is presented. We start from fixed train-set route, and then apply flexible train-set route that provides possible alternative turning activities to decrease the number of required train-sets. A case study based on Shanghai-Hangzhou high-speed rail line in China illustrates the methodology and compares the performance of various settings of perturbation tolerance, time window and train-set applications. INDEX TERMS Timetable, additional train, train-set circulation, tolerance of disruption, periodic structure.

“…However, it is not wise to apply the complete cyclic timetable model on Chinese railway due to its own features. Recently, researchers have shown an increased interest in an incomplete cyclic timetable model, an integration model of cyclic and noncyclic timetables, on China high-speed railways, such as [2,3]. When constructing incomplete cyclic timetables, the trains of short (or medium long) distances and high frequencies are scheduled as cyclic trains, and then trains of long distances or low frequencies need to be inserted into the planned cyclic timetable as extra acyclic trains.…”

Section: Introduction and Literature Reviewmentioning

confidence: 99%

A Branch and Bound Algorithm and Iterative Reordering Strategies for Inserting Additional Trains in Real Time: A Case Study in Germany

Mathematical Problems in Engineering

2015

With the aim of supporting the process of adapting railway infrastructure and future traffic needs, we have developed a method to insert additional trains efficiently to an existing timetable without introducing large consecutive delays to scheduled trains. In this work, the problem is characterized as a job-shop scheduling problem. In order to meet the limited time requirement and minimize deviations to the existing timetable, the modification that consists of retiming or reordering trains is implemented if and only if it potentially leads to a better solution. With these issues in mind, the problem of adding train paths is decomposed into two subproblems. One is finding the optimal insertion for a fixed order timetable and the other is reordering trains. The two subproblems are solved iteratively until no improvement is possible within a time limit of computation. An innovative branch and bound algorithm and iterative reordering strategy are proposed to solve this problem in real time. Unoccupied capacities are utilized as primary resources for additional trains and the transfer connections for passengers can be guaranteed in the new timetable. From numerical investigations, the proposed framework and associated techniques are tested and shown to be effective.