Maintaining a bus schedule

The maintaining of a regular schedule is important for the satisfactory and efficient operation of a bus service. The way in which a deviation from the regular schedule tends to amplify and give off schedule running of buses is investigated by considering a simple mathematical model of a service between a city and suburbs. It is shown that as buses pick up passengers through the city there is a tendency for buses to pair together. The behaviour of the model suggests several important factors which should be considered in the practical operation of a bus service (A).