MODELING RELIABILITY OF TRAIN ARRIVAL TIMES

This paper deals with the scheduling of trains so as to minimize train trip times while maximizing reliability of arrival times. The amount of risk of delay (RD) associated with a schedule is used as the reliab ility component of a constrained schedule optimization model. The pape r outlines the model developed to quantify the risk of delays to indiv idual trains, as well as to specific track segments and to the schedul e as a whole. The risk model, which deals with single track operations , can be used to estimate the likely impact on reliability of arrival times, changes in train frequencies, and operating practices; track an d station infrastructure investment strategies; and train technology u pgrading. An application of the model to the optimization of schedules on a track corridor is described. The results obtained using the mode l are compared with the schedules used by train operations planning st aff, in terms of overall delay and timetable reliability. The results highlight the significance of including a measure of timetable reliabi lity, such as risk of delays, in the objective function for scheduling optimization.