Optimal routing and scheduling of periodic inspections in large-scale railroad networks

Railroads use a set of rail inspection teams to periodically examine the status of rail tracks across the railroad network. The rail inspection scheduling problem (RISP) is a large-scale routing and scheduling problem where thousands of inspection tasks are to be scheduled subject to many complex constraints. This paper proposes a vehicle routing problem formulation for RISP and develops a customized heuristic algorithm to effectively solve the problem. Real-world case studies show that the proposed approach significantly outperforms commercial solvers and the state-of-art manual solution approach. The proposed approach has been adopted by a Class I railroad to enhance safety and operational efficiency.