Understanding causes of unpunctual trains : Delay contribution and critical disturbances

In this paper we define new concepts and metrics for improved understanding of causes to un-punctual trains. The metrics are denoted delay contribution and critical disturbance. Delay contribution can be interpreted as how much a specific disturbance contributes to the delay of a train and the critical disturbances can be interpreted as the disturbances that made the train become unpunctual. The metrics are applied in a test case with trains in southern Sweden. The results show that the metrics can provide a complementary view regarding causes to unpunctu-ality compared to standard methods and are able to pinpoint disturbances that made trains become unpunctual and separate them from disturbances that have less impact on the punctu-ality. The methods are useable in the continuous work to improve railway performance e.g., by prioritizing maintenance work that give best impact on punctuality