License: Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported license (CC BY-NC-ND 3.0)
When quoting this document, please refer to the following
DOI: 10.4230/OASIcs.ATMOS.2008.1584
URN: urn:nbn:de:0030-drops-15843
URL: http://dagstuhl.sunsite.rwth-aachen.de/volltexte/2008/1584/
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Frede, Lennart ; Müller-Hannemann, Matthias ; Schnee, Mathias

Efficient On-Trip Timetable Information in the Presence of Delays

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08002.Frede.1584.pdf (0.2 MB)


Abstract

The search for train connections in state-of-the-art commercial timetable information systems is based on a static schedule. Unfortunately, public transportation systems suffer from delays for various reasons.
Thus, dynamic changes of the planned schedule have to be taken into account. A system that has access to delay information of trains (and uses this information within search queries) can provide valid alternatives in case a train change breaks. Additionally, it can be used to actively guide passengers as these alternatives may be presented before the passenger is already stranded at a station due to a broken transfer.
In this work we present an approach which takes a stream of delay information and schedule changes on short notice (partial train cancellations, extra trains) into account. Primary delays of trains may cause a cascade of so-called secondary delays of other trains which have to wait according to certain waiting policies between connecting trains. We introduce the concept of a dependency graph to efficiently calculate and update all primary and secondary delays. This delay information is then incorporated into a time-expanded search graph which has to be updated dynamically.
These update operations are quite complex, but turn out to be not time-critical in a fully realistic scenario. We finally present a case study with data provided by Deutsche Bahn AG showing that this approach has been successfully integrated into our multi-criteria timetable information system MOTIS and can handle massive delay data streams instantly.

BibTeX - Entry

@InProceedings{frede_et_al:OASIcs:2008:1584,
  author =	{Lennart Frede and Matthias M{\"u}ller-Hannemann and Mathias Schnee},
  title =	{{Efficient On-Trip Timetable Information in the Presence of Delays}},
  booktitle =	{8th Workshop on Algorithmic Approaches for Transportation Modeling, Optimization, and Systems (ATMOS'08) },
  series =	{OpenAccess Series in Informatics (OASIcs)},
  ISBN =	{978-3-939897-07-1},
  ISSN =	{2190-6807},
  year =	{2008},
  volume =	{9},
  editor =	{Matteo Fischetti and Peter Widmayer},
  publisher =	{Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{http://drops.dagstuhl.de/opus/volltexte/2008/1584},
  URN =		{urn:nbn:de:0030-drops-15843},
  doi =		{10.4230/OASIcs.ATMOS.2008.1584},
  annote =	{Keywords: Timetable information system, primary and secondary delays dependency graph, dynamic graph update}
}

Keywords: Timetable information system, primary and secondary delays dependency graph, dynamic graph update
Collection: 8th Workshop on Algorithmic Approaches for Transportation Modeling, Optimization, and Systems (ATMOS'08)
Issue Date: 2008
Date of publication: 24.09.2008


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