HEADWAY ORDER SCHEME (HOS) HEURISTIC FOR THE RAILWAY RESCHEDULING OPTIMIZATION

Abstract

Railway rescheduling is a critical operation in delay management of passenger railway services. Most past studies related to railway rescheduling have put greater emphasis on how to minimize service delays when service is disrupted.  This paper presents a novel Headway and Order Scheme (HOS) heuristic to handle the conflict imposed by railway disruption by means of headway condition and reordering by priority in solving an optimization model for the railway rescheduling. The formulated multi-objective mathematical programming model aims at determining the adjusted schedules for trains based on some priority rules based on train category. The optimization model comprises of two objective functions which are, to minimize the sum of trains delay times and to maximize the reliability of services provided.Computational experiments focuses on Komuter trains rescheduling problems involving various trains priorities settings on Malaysian double track railways in which disruption incidences were mainly due to signaling switches problem and lasts bertween five to 15 inutes. The proposed model was solved using the preemptive goal programming approach. Results show that the model can generate the provisional timetable in 36 seconds and demonstrate that the priority order assigned to trains influenced the model’s obhective functions values. For five or 10 minutes duration of disruption, the model’s results indicated an average of 20 minutes delay and 88.9% service reliability.  The solutions obtained also satisfied all local rail operator’s restrictions.