The well-known Vehicle Scheduling Problem (VSP) is concerned with determining a set of
vehicle schedules to operate a given timetable at the lowest possible cost. This problem is often
encountered within bus operation in public transport.
The Simultaneous Vehicle Scheduling and Passenger Service Problem is based on the VSP, with
two significant modifications: First, the trips of the timetable are allowed to be shifted by a few
minutes to an earlier or later departure time, in the hope that this increased flexibility can lead
to a lower operating cost, without introducing significant changes to the timetable. Secondly, a
measure of passenger service is introduced for the evaluation of solutions, in order to control the
effects of this timeshifting.
The measure of passenger service used in the calculations is based on the passenger waiting
times at transfers between different lines. These transfers can take place between two lines that
are both under the control of the model (and thereby have varying departure times), or to/from
a line that is external to the model (and thereby has a fixed timetable). It should also be noted
that passenger waiting times considered in this work, are only waiting times at transfers and not
those experienced by passengers entering the system.
An application from the Greater Copenhagen Area is studied, dealing with the network of local
express buses, which is build up around the local train network. A schematic overview of this
network can be seen in Figure 1, where the dashed lines represent train lines (roughly with the
form of a fan), and the solid lines (all shades) show the available bus lines, of which most are
perpendicular to the train lines.