Train routing selection problem: Ant colony optimization versus integer linear programming

The real-time Railway Traffic Management Problem (rtRTMP) is the problem of detecting and solving time-overlapping conflicting request done by multiple trains on same track resources. It typically consists in taking retiming, reordering or rerouting train actions such a way that propagation disturbances railway network minimized. rtRTMP an NP-Hard finding good strategy to simplifying its solution process paramount obtain quality solutions short computation. Solving Train Routing Selection (TRSP) aims do so, limiting number routing variables through pre-processing selects most promising alternatives among available ones for each order reduce size instances. This paper studies performance Ant Colony Optimization (ACO) algorithm problem. An integer linear programming formulation TRSP presented solved using commercial software, it considered as benchmark. Computational experiments are performed two practical case French infrastructure: line near city Rouen Lille terminal station area. ACO solver perform comparably only small instances both able find optimal solutions. However, larger instances, outperforms terms computation time quality.