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.
