The 2007 Dutch train timetable, which started on 10 December 2006, has been made more robust with help of CWI researcher Lex Schrijver and programmer Adri Steenbeek. This was pointed out by Leo Kroon from Erasmus University and NS Reizigers on the annual day for relations of CWI on 16 November, 2006.
Designing a timetable for the Dutch railroad-system - one of the busiest in the world - is very complex. Thousands of interrelated constraints have to be satisfied, like desired frequencies, travel and change times, availability of rolling stock and distances between trains. Further, the robustness and the personnel schedules should be optimized. In the 1990s CWI developed CADANS, the combinatorial algebraic timetable algorithm for Dutch railways, which was extended and improved over the years. With this software the Dutch Railways (NS) can compare several aspects quantitatively, and choose a good balance between them - like in the 2007 train timetable.
Kroon was one of the keynote speakers who discussed the four themes which will inspire CWI research in the years to come: data explosion, societal logistics, earth and life sciences, and service-oriented computing. Other speakers were Alexander Rinnooy Kan (SER, the Social and Economic Council of the Netherlands), Frank Kelly (University of Cambridge), Hans Westerhoff (University of Manchester, Vrije Universiteit Amsterdam, Universiteit van Amsterdam) and Mike Papazoglou (Tilburg University). A lively discussion took place during the reception and the dinner afterwards, offered by CWI on the occasion of its 60th anniversary.
More information can be found in a background article on CADANS in ERCIM News (1995)