A Tutorial on Train Timetabling and Train Platforming Problems

In this tutorial, we give an overview of two fundamental problems arising in the optimization of a railway system: the Train Timetabling Problem (TTP) and the Train Platforming Problem (TPP). These problems correspond to two main phases that are usually optimized in close sequence. First, in the TTP phase, a schedule of the trains in a railway network is determined. A schedule consists of the arrival and departure times of each train at each (visited) station. Second, in the TPP phase, one needs to determine a topping platform and a routing for each train inside each (visited) station, according to the schedule found in the TTP phase. Due to the complexity of the two problems, an integrated approach is generally hopeless for real-world instances. Hence, the two phases are considered separately and optimized in sequence. Although there exist several versions for both problems, depending on the infrastructure manager and train operators requirements, we do not aim at presenting all of them, but rather at introducing the reader to the topic using small examples. We present models and solution approaches for the two problems in a didactic way and always refer the reader to the corresponding articles for technical details