Track inspection schedule planning with time and safety considerations

The automated track inspection is one of the most common inspection methods used to monitor the health of the rail tracks. Automated inspection is commonly carried out by vehicles equipped with technology capable of ultrasonic track inspection. Scheduling an automated inspection vehicle is, therefore, crucial to optimise the safety benefits achieved from inspection. In this study, we introduce a bi-objective track inspection scheduling problem for an automated ultrasonic inspection vehicle. This model maximises the safety benefits and minimises the time required for completing the scheduled inspections. We propose an evolutionary scheduling heuristic and compare it to a naive greedy scheduling method. Through a numerical study, we conclude that the evolutionary scheduling heuristic outperforms the greedy scheduling heuristic. Furthermore, we note that considering two objectives for track inspection planning leads to inspection schedules with higher safety benefits per unit inspection time.