TOPSU - RDM a simulation platform for online railway delay management

Delays in a railway network is a common problem that railway companies face in their daily operations. When a train gets delayed, it may either be beneficial to let a connecting train wait so that passengers in the delayed train do not miss their connection, or it may be beneficial to let the connecting train depart on time to avoid further delays. These decisions naturally depend on the global structure of the network and on the schedule. The railway delay management (RDM) problem (in a broad sense) is to decide which trains have to wait for connecting trains and which trains have to depart on time. The offline version (i.e. when all delays are known in advance) is already NP-hard for very special networks. In this paper we show that the online railway delay management (ORDM) problem is PSPACE-hard, and we present TOPSU – RDM, a simulation platform for evaluating and comparing different heuristics for the ORDM problem with stochastic delays. Our novel approach is to separate the actual simulation and the program that implements the decision making policy, thus enabling implementations of different heuristics to “compete” on the same instances and ∗The first three authors have been partially supported by the European Regional Development Fund (ERDF). †Part of this work was done while this author was on leave at Technical University Berlin. ‡This authors work was partially supported by the ARRIVAL project, within the 6th Framework Programme of the European Comission under contract no. FP6-021235-2. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. SIMUTools 2008 March 3-7, 2008, Marseille, France Copyright 2008 ACM ISBN 978-963-9799-20-2 ...$5.00. delay distributions. For RDM and other logistic planning processes, it is our goal to bridge the gap between theoretical models, which are accessible to theoretical analysis, but often too far away from practice, and the methods which are used in practice today, whose performance is almost impossible to measure.