Thumbnail Image

The Periodic Assignment Problem (PAP) May Be Solved Greedily

Liebchen, Christian

Inst. Mathematik

Many public transportation companies operate their networks periodically. One major step in their planning process is to construct a periodic timetable for one abstract period, independently from times during the day. In this paper we show that we may evaluate a periodic timetable very quickly with the number of vehicles required to operate it. This is due to the fact that the Periodic Assignment Problem (PAP) can be solved by a greedy approach. It helps us, at least within a genetic algorithm, to cope with the quadratic objective function in the problem of finding a periodic timetable requiring as few vehicles as possible.