Assessing the Compatibility of Railway Station Layouts and Mixed Heterogeneous Traffic Patterns by Optimization-Based Capacity Estimation

Abstract

The operations performance of a railway station depends on the compatibility of its layout and the traffic pattern. It is necessary to determining an adaptable station layout for a railway station in accordance with its complex traffic pattern during the design phase. This paper assesses the railway station layout from a capacity perspective. In particular, this paper addresses an optimization-based capacity estimation approach for the layout variants of a railway station (i.e., the number of siding tracks and the structure of the connections in between) considering the traffic pattern variants. A mixed integer programming model for microscopic timetable compression is applied to calculate the occupation rate of the given traffic pattern with flexible route choices and train orders. A novel “schedule-and-fix” heuristic algorithm is proposed to solve large-scale instances efficiently. In the case study, we evaluate the performance of the schedule-and-fix method compared with the benchmark solvers Gurobi and CP-SAT. Applying the proposed method, we compare the capacity performances of the two station design schemes, i.e., one with a flyover and the other without. The result shows that, for the given instance, building a flyover gains capacity benefits as it reduces the potential conflict in the throat area. However, the level of benefit depends on the combination of trains. It is necessary to build the flyover when the proportion of turn-around trains is more than 70% from the perspective of station capacity.