Algorithmic Methods for Railway Optimization Dagstuhl Seminar

From 20.06.04 to 25.06.04, the Dagstuhl Seminar 04261 Algorithmic Methods for Railway Optimization was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The rst section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available. An Optimization Model for Railway Track Auctions Ralf Borndörfer (K. Zuse Zentrum Berlin, D) The talk discusses an auctioning approach to establish a rail track market, in which di erent train operating companies (TOCs) compete for tracks and timeslots on the same network. We propose timetabled tracks (TTs), i.e., the infrastructure resources in time and space consumed by a single train, as the commodity of this market. Auctioning such TTs leads to the consideration of the Optimal Track Allocation Problem (OPTRA) to select from a set of bids for TTs a con ict free timetable of maximum value. The auction can then be organized as a sequence of OPTRAs with rising bids. The OPTRA itself can be modeled as a multicommodity ow problem, introducing a commodity for each TT, and attacked with integer programming techniques. As the complexity of the railway system prohibits a detailed planning of TTs for relevant scenarios at this level, our implementation resorts to simpli cations in network structure and train operation such as standardized dynamics and Dagstuhl Seminar Proceedings 04261 Algorithmic Methods for Railway Optimization http://drops.dagstuhl.de/opus/volltexte/2006/471 2 L. Kroon, D. Wagner, F. Wagner and C. Zaroliagis train types, topological simpli cations, etc. such that the model can only result in a coarse plan. In this way, scenarios covering a part of the long distance network of Deutsche Bahn form Hannover to Kassel, a time horizon of six hours, and about 1,000 bids for TTs are compuationally feasible using standard methods. First auctioning experiments indicate substantial potentials for routing additional tra c through the existing network.