Determinants of Delay Incident Occurrence in Urban Metros

Document Type

Journal Article

Publication Date


Subject Area

mode - subway/metro, place - north america, organisation - management, operations - performance, operations - reliability


reliability, train service, delays, operations management, health and safety, management practices


The reliability of train service is a key objective of metro management and a major part of a successful operation. An occurrence of incidents in the network is likely to cause delays to the train service and disorder in the punctuality and regularity of the metro operation and hence affects the service reliability of the metro system. This result suggests a way to improve train service reliability by reducing the occurrence of incidents in urban metro systems. This paper used statistical techniques to identify the main factors that explained the variation in the number of delay incidents across 42 metro lines of 15 different metro systems from 2005 to 2009. The main factors that explained differences in incident performance across urban metro lines were the technology of the mode of train operation, the level of passenger demand, the service level operated during peak periods, and the practical capacity available. In contrast, engineering and usually fixed factors such as the type of track support, the type of rail connection, and the type of rolling stock wheel did not affect the level of incidents. The findings also suggested that metro-specific factors (e.g., differences in maintenance and management practices, operations management, and health and safety procedures) helped to explain the variation in incident performance across urban metros.


Permission to publish the abstract has been given by Transportation Research Board, Washington, copyright remains with them.