Integrating line planning, timetabling, and vehiclescheduling: a customer-oriented heuristic

Abstract Given an existing public transportation network, the classic planning
process in public transportation is as follows: In a first step, the lines are designed; in
a second step a timetable is calculated and finally the vehicle and crew schedules are
planned. The drawback of this sequence is that the main factors for the costs (i.e. the
number of vehicles and drivers needed) are only determined in a late stage of the
planning process.
We hence suggest to reorder the classic sequence of the planning steps: In our
new approach we first design the vehicle routes, then split them to lines and finally
calculate a (periodic) timetable. The advantage is that costs can be controlled during
the whole process while the objective in all three steps is customer-oriented.
In the paper we formulate an integrated model from which we develop this new
approach, discuss the complexity of the resulting problems, and present a heuristic
which we applied within a case study, optimizing the local bus system in Göttingen,
Germany.
1 Motivation and related literature
According to Desaulniers and Hickman (2007) the planning process in public transportation
includes several phases such as strategic planning (e.g. network design),
tactical planning (as line planning or timetabling), operational planning (e.g. vehicle
scheduling) and real time control. The usual sequence of these planning steps is
sketched in Fig. 1, see e.g. Ceder and Wilson (1986), Liebchen and Möhring (2007).