SCHEDULING FOR DEPLETED SERVICES

Two mathematical models, one analytic and the other relying on computer simulation, were used to investigate the effects of cancelled buses on passenger waiting times, and also the improvements which could be brought about by rescheduling. Two rescheduling strategies were evaluated by the analytic model, the first to provide equal headways for available buses in a schedule changing daily, while the second provided a reserve pool of buses to replace cancelled buses in a new service scheduled at a lower frequency. The simulation model was used to represent two real bus services. It is estimated that in situations where services are consistently running behind complement, rescheduling could produce savings in passenger waiting time amounting to some 20000 hours per year for each bus missing from the original service. /TRRL/