A Mixed Integer Linear Programming Model with Heuristic Improvements for Single-Track Railway Rescheduling Problem

A rescheduling algorithm for trains on a single-track railway was developed in case of disturbances that would cause conflicts between trains. This is based mixed integer linear programming (MILP) with speed-up routines. The model considers station capacities explicitly (i.e., the number available tracks meeting and overtaking operations). Because too hard solvers (CPLEX this study) to tackle, three routines were devised when These are greedy heuristic reduce solution space, using lazy constraint attribute solver multiobjective approach find good initial feasible conforms actual operation. tested hypothetical rail line different sizes timetable instances disturbed maximum two-hour time horizon. It managed solve hardest within three-minute limit thus minimizing total weighted delay rescheduled optimality gap metric used show effectiveness efficiencies heuristics developed.