Inter-modal transfer time is a significant component of transit travel from the perspective of passengers, and schedule coordination is one possible strategy to reduce the inconvenience of transfers. This study developed an optimization model for generating transit timetables that minimize transfer-related times. The model attempts to find an optimal timetable by shifting the existing timetable and/or adding holding time to the timetable to optimize the transfers from transit units on a feeder commuter route to transit units on a receiver suburban route. Analytical models are developed to estimate the waiting time of the transfer passengers, and also to determine the influence of the schedule modification on the waiting times of non-transfer passengers. The models explicitly incorporate the variability of transit vehicle arrivals, assumed to follow a lognormal distribution. This study employs Genetic Algorithms (GA) as the solution approach to find an optimal schedule. The developed model is tested using schedule data from a local transit service in the City of Brampton, Canada. The results show that the model reduces effectively the total transfer and waiting times through the modification of the current schedule.
Abstract