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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2007.06.062 Byline: Xavier Delorme (a), Xavier Gandibleux (b), Joaquin Rodriguez (c) Keywords: Transportation; Multiple objective programming; Railway infrastructure capacity; Timetable stability; Shortest path Abstract: This research deals with a real-world planning problem in railway infrastructure operations. It is part of the RECIFE project, which seeks to develop a decision support software to help evaluate the capacity of a rail junction or station. To this end, the project is working on a timetable optimization model, as well as timetable evaluation modules. This paper presents a module for evaluating timetable stability, which uses an original method based on delay propagation and using shortest path problem resolution. A didactic example and a complete case study applying this method to the Pierrefitte-Gonesse junction are also presented. Author Affiliation: (a) Centre Genie Industriel et Informatique, Ecole Nationale Superieure des Mines de Saint-Etienne, 158 cours Fauriel, F42023 Saint-Etienne Cedex 2, France (b) LINA, Universite de Nantes, 2 rue de la Houssiniere BP 92208, F44322 Nantes Cedex 03, France (c) INRETS-ESTAS, 20 rue Elisee Reclus, F59650 Villeneuve d'Ascq, France Article History: Received 15 January 2007; Accepted 18 June 2007

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.apergo.2008.04.010 Byline: Brendan Ryan (a), John R. Wilson (a)(b), Sarah Sharples (a), Theresa Clarke (c) Keywords: Rail human factors; Survey administration and analysis; Comparisons of roles Abstract: REQUEST, the Rail Ergonomics Questionnaire, has been designed to survey attitudes and opinions of railway signallers and those in associated roles on a range of human factors such as job satisfaction, the workplace, culture or stress. The development of the survey instrument has been described in Ryan et al. [2008. Developing a rail ergonomics questionnaire (REQUEST). Appl. Ergon., doi:10.1016/j.apergo.2008.04.006.]. The present paper presents an overview of findings from this national survey which achieved a sample size of 3889 and a response rate of 83%. Findings are compared by different roles (e.g. signaller, controller) on a range of main scales and responses to additional questions in the survey. Ratings from the largest of the occupational groups, the signaller at 83.1% of the overall population, have been compared according to different types of signalling system used, identifying different characteristics in the use of lever, panel and VDU signalling systems. Comparisons of signallers' ratings by geographical location have produced findings of interest at different layers of management of the organisation, identifying locations with high or low ratings on a range of scales. The findings provide valuable information for the client organisation, using direct input from frontline staff on a range of human factors issues. This was a large survey, one of the largest ever civilian human factors surveys, involving lengthy, often repetitive and frequently complex analyses. Lessons learned within the administration of the survey, the analysis of the data and dissemination of the findings will be of interest to researchers. An overview of the scope of analyses of the database is introduced, in addition to proposals for further development of the survey instrument. Author Affiliation: (a) Institute for Occupational Ergonomics, University of Nottingham, University Park, Nottingham NG7 2RD, UK (b) School of Risk and Safety Science, University of New South Wales, Australia (c) Ergonomics National Specialist Team, Network Rail, Melton Street, London, UK Article History: Received 9 July 2007; Accepted 3 April 2008

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2006.10.034 Byline: Andrea D'Ariano (a), Dario Pacciarelli (b), Marco Pranzo (c) Keywords: Train scheduling; Real-time conflict resolution; Alternative graph; Branch and bound algorithm Abstract: The paper studies a train scheduling problem faced by railway infrastructure managers during real-time traffic control. When train operations are perturbed, a new conflict-free timetable of feasible arrival and departure times needs to be re-computed, such that the deviation from the original one is minimized. The problem can be viewed as a huge job shop scheduling problem with no-store constraints. We make use of a careful estimation of time separation among trains, and model the scheduling problem with an alternative graph formulation. We develop a branch and bound algorithm which includes implication rules enabling to speed up the computation. An experimental study, based on a bottleneck area of the Dutch rail network, shows that a truncated version of the algorithm provides proven optimal or near optimal solutions within short time limits. Author Affiliation: (a) Department of Transport and Planning, Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands (b) Dipartimento di Informatica e Automazione, Universita degli Studi Roma Tre, via della vasca navale, 79 - 00146 Roma, Italy (c) Dipartimento di Ingegneria dell'Informazione, Universita di Siena, via Roma, 56 - 53100 Siena, Italy Article History: Received 27 October 2005; Accepted 5 October 2006

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2005.10.037 Byline: Fausto Pedro Garcia Marquez (a), Diego Jose Pedregal Tercero (a), Felix Schmid (b) Keywords: Maintenance; Reliability; Unobserved Components models; Condition monitoring; Points mechanisms Abstract: Railways are experiencing a fundamental transformation. The introduction of high speed networks and the increased traffic levels on suburban routes and freight lines require new technologies for both railway infrastructure and trains, all of which must be subjected to rigorous quality control before and during operation and must be supported with effective maintenance processes during their operating lives. Safety in railway infrastructure provision must be ensured by all the main components operating reliably all the time. From an economic, quality and safety point of view, points are probably one of the most critical infrastructure elements in railway transportation. Most problems with points mechanisms are associated with either wear of components or movements of the sleepers and rails resulting from the normal behaviour of ballasted track. Therefore, railway points require regular adjustment to compensate for wear in switch rails, cams, hinges of linkages and detection switches. Consequently, a dependable method of wear control is required. Ideally, this should involve only minimal human intervention, particularly with regard to wear of the tracks. The method for assessing wear proposed in this paper is based on a robust remote monitoring system. It involves the collection and transmission of time varying data and the analysis of the signals. The authors put forward models to monitor wear based on the signal analysed for detecting the state of points mechanisms. The models explored in this paper in real time belong to the so called Unobserved Components class of models, set up in a State Space framework. The unknown elements in the system matrices are estimated by a maximum likelihood algorithm, and they are generally updated each time new data becomes available. The system developed has been tested in numerous experiments to demonstrate its efficiency and it is able to find potential hazards. Typical wear-inducing faults were introduced intentionally during the experiments on which the present paper is based. Author Affiliation: (a) ETSII de Ciudad Real, Universidad de Castilla-La Mancha, C/Erillas 42, 45516 La Puebla de Montalban (Toledo), Spain (b) Mechanical Engineering Department, Sheffield University, England, United Kingdom Article History: Received 5 March 2005; Accepted 27 October 2005

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2004.12.013 Byline: P. Vansteenwegen, D. Van Oudheusden Keywords: Robustness; Linear programming; Timetabling; Railway connections; Buffer times Abstract: In order to improve passenger service, a waiting cost function, weighting different types of waiting times and late arrivals, is designed and minimised. The approach is applied to a small part of the Belgian railway network. In the first phase of the approach, ideal buffer times are calculated to safeguard connections when the arriving train is late. These buffer times are based on the delay distributions of the arriving trains and on the weighting of different types of waiting times. In a second phase, standard linear programming is used to construct an improved timetable with well-scheduled connections and, whenever possible, with ideal buffer times. Simulation compares different timetables and optimises the LP timetable. For the case of the Belgian railway network, the final result is a timetable with well-scheduled connections and a waiting cost that is 40% lower than the current timetable. Since only LP modelling is applied, the proposed technique is very promising for developing better timetables -- even for very extensive railway networks. Author Affiliation: Centrum voor Industrieel Beleid, Katholieke Universiteit Leuven, Celestijnenlaan 300A, 3001 Leuven, Belgium Article History: Received 21 November 2003; Accepted 9 December 2004

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2004.10.010 Byline: Michiel J.C.M. Vromans (a), Rommert Dekker (b), Leo G. Kroon (c)(d) Keywords: Railways; Transportation; Reliability; Heterogeneity; Simulation Abstract: Reliability is one of the key factors in transportation, both for passengers and for cargo. This paper examines reliability in public railway systems. Reliability of railway services is a complex matter, since there are many causes for disruptions and at least as many causes for delays to spread around in space and time. One way to increase the reliability is to reduce the propagation of delays due to the interdependencies between trains. In this paper we attempt to decrease these interdependencies by reducing the running time differences per track section and by thus creating more homogeneous timetables. We also introduce two heuristic measures, that can be used to evaluate the homogeneity of a timetable. Because of the complexity of railway systems, we use network wide simulation for the analysis of the alternative timetables. We report on both theoretical and practical cases. Besides a comparison of different timetables, also general timetabling principles are deduced. Author Affiliation: (a) ProRail, Infrastructure Planning Department, Utrecht, The Netherlands (b) Department of Econometrics and Operations Research, School of Economics, Erasmus University Rotterdam, The Netherlands (c) Department of Decision and Information Management, School of Management, Erasmus University Rotterdam, The Netherlands (d) Logistics Department, Netherlands Railways, Utrecht, The Netherlands Article History: Received 5 January 2004; Accepted 22 October 2004

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ejor.2004.04.036 Byline: Jan-Willem Goossens (a), Stan van Hoesel (a), Leo Kroon (b) Keywords: Integer programming; Combinatorial optimisation; Railway transportation Abstract: An important strategic element in the planning process of a railway operator is the development of a line plan, i.e., a set of routes (paths) on the network of tracks, operated at a given hourly frequency. The models described in the literature have thus far considered only lines that halt at all stations along their route. In this paper we introduce several models for solving line planning problems in which lines can have different halting patterns. Correctness and equivalence proofs for these models are given, as well as an evaluation using several real-life instances. Author Affiliation: (a) Department of Quantitative Economics, University of Maastricht, P.O. Box 616, 6200 MD Maastricht, The Netherlands (b) Rotterdam School of Management, Erasmus University Rotterdam, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands Article History: Received 14 May 2003; Accepted 19 April 2004

The impact of 1993 reform of the British railway industry on investments is examined.