@article{BorndoerferKarbstein, author = {Bornd{\"o}rfer, Ralf and Karbstein, Marika}, title = {Neue Planungsinstrumente nutzen: Das Verkehrsangebot verbessern und Kosten sparen}, series = {Verkehr und Technik}, volume = {68}, journal = {Verkehr und Technik}, number = {7}, pages = {239 -- 243}, abstract = {Wir illustrieren anhand des Liniennetzes der Stadt Potsdam das Potenzial mathematischer Methoden der Angebotsplanung. Wir zeigen, dass das "bestm{\"o}gliche" Verkehrsangebot stark von planerischen Vorgaben beeinflusst wird, mit denen man die Erreichung unterschiedlicher und teilweise gegenl{\"a}ufiger Ziele steuern kann. Die Komplexit{\"a}t des Systems f{\"u}hrt zum Auftreten von R{\"u}ckkoppelungseffekten, die man nicht mit Hilfe von Daumenregeln beherrschen kann. Vielmehr ist der Einsatz moderner Planungsverfahren in einer interdisziplin{\"a}ren Zusammenarbeit von politischen Entscheidungstr{\"a}gern, Verkehrsingenieuren und Mathematikern notwendig, um die aktuellen Herausforderungen in der Verkehrsplanung zu meistern. Der Artikel dokumentiert einen Beitrag zum 7. {\"O}PNV Innovationskongress des Ministeriums f{\"u}r Verkehr und Infrastruktur des Landes Baden-W{\"u}rttemberg, der vom 9.-11. M{\"a}rz 2015 in Freiburg stattfand.}, language = {de} } @misc{BorndoerferHoppmannKarbstein, author = {Bornd{\"o}rfer, Ralf and Hoppmann, Heide and Karbstein, Marika}, title = {Passenger Routing for Periodic Timetable Optimization}, issn = {1438-0064}, doi = {10.1007/s12469-016-0132-0}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-56739}, abstract = {The task of periodic timetabling is to schedule the trips in a public transport system by determining arrival and departure times at every station such that travel and transfer times are minimized. To date, the optimization literature generally assumes that passengers do not respond to changes in the timetable, i.e., the passenger routes are fixed. This is unrealistic and ignores potentially valuable degrees of freedom. We investigate in this paper periodic timetabling models with integrated passenger routing. We show that different routing models have a huge influence on the quality of the entire system: Whatever metric is applied, the performance ratios of timetables w.r.t. to different routing models can be arbitrarily large. Computations on a real-world instance for the city of Wuppertal substantiate the theoretical findings. These results indicate the existence of untapped optimization potentials that can be used to improve the efficiency of public transport systems.}, language = {en} } @article{BorndoerferKarbstein, author = {Bornd{\"o}rfer, Ralf and Karbstein, Marika}, title = {Metric inequalities for routings on direct connections with application to line planning}, series = {Discrete Optimization}, volume = {18}, journal = {Discrete Optimization}, pages = {56 -- 73}, abstract = {We consider multi-commodity flow problems in which capacities are installed on paths. In this setting, it is often important to distinguish between flows on direct connection routes, using single paths, and flows that include path switching. We derive a feasibility condition for path capacities supporting such direct connection flows similar to the well-known feasibility condition for arc capacities in ordinary multi-commodity flows. The condition can be expressed in terms of a class of metric inequalities for routings on direct connections. We illustrate the concept on the example of the line planning problem in public transport and present an application to large-scale real-world problems.}, language = {en} } @inproceedings{BorndoerferHoppmannKarbstein2015, author = {Bornd{\"o}rfer, Ralf and Hoppmann, Heide and Karbstein, Marika}, title = {Timetabling and Passenger Routing in Public Transport}, series = {Proceedings of Conference on Advanced Systems in Public Transport 2015 (CASPT2015)}, booktitle = {Proceedings of Conference on Advanced Systems in Public Transport 2015 (CASPT2015)}, year = {2015}, abstract = {The task of timetabling is to schedule the trips in a public transport system by determining periodic arrival and departure times at every station. The goal is to provide a service that is both attractive for passengers and can be operated economically. To date, timetable optimization is generally done with respect to fixed passenger routes, i.e., it is assumed that passengers do not respond to changes in the timetable. This is unrealistic and ignores potentially valuable degrees of freedom. We investigate in this paper periodic timetabling models with integrated passenger routing. We propose several models that differ in the allowed passenger paths and the objectives. We compare these models theoretically and report on computations on real-world instances for the city of Wuppertal.}, language = {en} } @misc{BorndoerferKarbstein, author = {Bornd{\"o}rfer, Ralf and Karbstein, Marika}, title = {Metric Inequalities for Routings on Direct Connections with Application in Line Planning}, issn = {1438-0064}, doi = {10.1016/j.disopt.2015.07.004}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-53507}, abstract = {We consider multi-commodity flow problems in which capacities are installed on paths. In this setting, it is often important to distinguish between flows on direct connection routes, using single paths, and flows that include path switching. We derive a feasibility condition for path capacities supporting such direct connection flows similar to the feasibility condition for arc capacities in ordinary multi-commodity flows. The concept allows to solve large-scale real-world line planning problems in public transport including a novel passenger routing model that favors direct connections over connections with transfers.}, language = {en} } @misc{BorndoerferHoppmannKarbstein, author = {Bornd{\"o}rfer, Ralf and Hoppmann, Heide and Karbstein, Marika}, title = {Timetabling and Passenger Routing in Public Transport}, series = {Appeard in: Proceedings of Conference on Advanced Systems in Public Transport 2015 (CASPT2015)}, journal = {Appeard in: Proceedings of Conference on Advanced Systems in Public Transport 2015 (CASPT2015)}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-55305}, abstract = {The task of timetabling is to schedule the trips in a public transport system by determining periodic arrival and departure times at every station. The goal is to provide a service that is both attractive for passengers and can be operated economically. To date, timetable optimization is generally done with respect to fixed passenger routes, i.e., it is assumed that passengers do not respond to changes in the timetable. This is unrealistic and ignores potentially valuable degrees of freedom. We investigate in this paper periodic timetabling models with integrated passenger routing. We propose several models that differ in the allowed passenger paths and the objectives. We compare these models theoretically and report on computations on real-world instances for the city of Wuppertal.}, language = {en} } @misc{BorndoerferKarbstein, author = {Bornd{\"o}rfer, Ralf and Karbstein, Marika}, title = {Neue Planungsinstrumente nutzen: Das Verkehrsangebot verbessern und Kosten sparen}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-55439}, abstract = {Wir illustrieren anhand des Liniennetzes der Stadt Potsdam das Potenzial mathematischer Methoden der Angebotsplanung. Wir zeigen, dass das "bestm{\"o}gliche" Verkehrsangebot stark von planerischen Vorgaben beeinflusst wird, mit denen man die Erreichung unterschiedlicher und teilweise gegenl{\"a}ufiger Ziele steuern kann. Die Komplexit{\"a}t des Systems f{\"u}hrt zum Auftreten von R{\"u}ckkoppelungseffekten, die man nicht mit Hilfe von Daumenregeln beherrschen kann. Vielmehr ist der Einsatz moderner Planungsverfahren in einer interdisziplin{\"a}ren Zusammenarbeit von politischen Entscheidungstr{\"a}gern, Verkehrsingenieuren und Mathematikern notwendig, um die aktuellen Herausforderungen in der Verkehrsplanung zu meistern. Der Artikel dokumentiert einen Beitrag zum 7. {\"O}PNV Innovationskongress des Ministeriums f{\"u}r Verkehr und Infrastruktur des Landes Baden-W{\"u}rttemberg, der vom 9.-11. M{\"a}rz 2015 in Freiburg stattfand.}, language = {de} }