Reducing Passenger Delays by Rolling Stock Rescheduling

Delays are a major nuisance to railway passengers. The extent to which a delay propagates, and thus affects the passengers, is influenced by the assignment of rolling stock. We propose to reschedule the rolling stock in such a way that the passenger delay is minimized and such that objectives on passenger comfort and operational efficiency are taken into account. We refer to this problem as the Passenger Delay Reduction Problem (PDRP). We propose two models for this problem, which are based on two dominant streams of literature for the traditional Rolling Stock Rescheduling Problem. The first model is an arc formulation of the problem, while the second model is a path formulation. We test the effectiveness of these models on instances of Netherlands Railways (NS). The results show that the rescheduling of rolling stock can significantly decrease the passenger delays in the system. Especially allowing flexibility in the assignment of rolling stock at terminal stations turns out to be effective in reducing the delays. Moreover, we show that the arc formulation based model performs best in finding high-quality solutions within the limited time that is available in the rescheduling phase.