This book focuses on the adding train paths (ATP) problem for scheduling additional train services in an initial cyclic timetable. Many contributions are made to addressing the problems.(1)The hybrid timetable concept namedcyclic + noncyclic timetable is proposed to describe the pattern of the timetable. (2) The integration of timetable scheduling and rescheduling problems is considered both the disruptions in existing operations and establishments of schedules for extra trains.(3) An event-activity graph is constructed to characterize the ATP problems. (4)The initial trains ′modifications, additional trains′ schedules and train-set circulation are decided simultaneously to cope with the shortage of train-set capacity. This book is to serve as both a graduate level text and a general professional reference. It is oriented towards the readers who have had an introductory level course in train operation planning.