Selected Papers from the 8th Workshop on Algorithmic Approaches for Transportation Modeling, Optimization, and Systems

Proceedings of the 8thWorkshop on Algorithmic Approaches for Transportation Modeling, Optimization, and Systems, held on Septmeber 18 in Karlsruhe, Germany. ATMOS 2008 Preface 8th Workshop on Algorithmic Approaches for Transportation Modeling, Optimization, and Systems The 8th ATMOS workshop was held in Karlsruhe, September 18, 2008, within ALGO, a set of meetings related to algorithms. The series of ATMOS workshops, starting in Heraklion in 2001, continuing in Malaga in 2002, Budapest in 2003, Bergen in 2004, Palma de Mallorca in 2005, Zürich in 2006, and Sevilla in 2007 is by now an established series of meetings between algorithms researchers dealing with transportation problems, and practitioners, mainly from railways. Joint work of: Fischetti, Matteo; Widmayer, Peter Extended Abstract: http://drops.dagstuhl.de/opus/volltexte/2008/1593 Dynamic Algorithms for Recoverable Robustness Problems Recently, the recoverable robustness model has been introduced in the optimization area. This model allows to consider disruptions (input data changes) in a uni ed way, that is, during both the strategic planning phase and the operational phase. Although the model represents a signi cant improvement, it has the following drawback: we are typically not facing only one disruption, but many of them might appear one after another. In this case, the solutions provided in the context of the recoverable robustness are not satisfying. In this paper we extend the concept of recoverable robustness to deal not only with one single recovery step, but with arbitrarily many recovery steps. To this aim, we introduce the notion of dynamic recoverable robustness problems. We apply the new model in the context of timetabling and delay management problems. We are interested in nding e cient dynamic robust algorithms for solving the timetabling problem and in evaluating the price of robustness of the proposed solutions. ATMOS 2008 8th Workshop on Algorithmic Approaches for Transportation Modeling, Optimization, and Systems http://drops.dagstuhl.de/opus/volltexte/2008/1592 2 M. Fischetti, P. Widmayer