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  • 1.
    Ait Ali, Abderrahman
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Swedish National Road and Transport Research Institute (VTI), Sweden.
    Lindberg, Per Olov
    Swedish National Road and Transport Research Institute (VTI), Sweden.
    Eliasson, Jonas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Nilsson, Jan-Eric
    Swedish National Road and Transport Research Institute (VTI), Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    A disaggregate bundle method for train timetabling problems2020In: Journal of Rail Transport Planning & Management, ISSN 2210-9706, E-ISSN 2210-9714, Vol. 16, article id 100200Article in journal (Refereed)
    Abstract [en]

    The train timetabling problem (TTP) consists of finding a feasible timetable for a number of trains which minimises some objective function, e.g., sum of running times or deviations from ideal departure times. One solution approach is to solve the dual problem of the TTP using so-called bundle methods. This paper presents a new bundle method that uses disaggregate data, as opposed to the standard bundle method which in a certain sense relies on aggregate data. We compare the disaggregate and aggregate methods on realistic train timetabling scenarios from the Iron Ore line in Northern Sweden. Numerical results indicate that the proposed disaggregate method reaches better solutions faster than the standard aggregate approach.

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  • 2.
    Andersson, Emma
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Trafikverket.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Increasing robustness at single-track lines using the indicator robustness in passing pointss2023Conference paper (Other academic)
    Abstract [en]

    When several trains are planned to use the same infrastructure resource, there is always a risk for spreading of delays, which can be hard to recover from. It is a challenge for the Infrastructure Manager to make timetables that accommodate as much traffic as possible, without causing bad on-time performance. Timetable planners are in need of quantitative indicators to assess timetable robustness and accurate methods for how to make the timetable more robust.

    In this paper we assess the robustness for single-track lines with non-periodic timetables. At single-track lines, trains use the line for running in both directions and the trains can only pass or overtake each other at passing loops. This makes the system more sensitive for delays. In this paper we present a robustness indicator which captures the dependencies between trains at a single-track line. The indicator can be used to illustrate weaknesses in a timetable and also to indicate where and how to insert more robustness. In a simulation study, we show that it is possible to improve the performance by making small timetable adjustments according the indicator, without increasing runtimes or capacity utilization.

  • 3.
    Andersson, Emma
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Törnquist Krasemann, Johanna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Improved Railway Timetable Robustness for Reduced Traffic Delays – a MILP approach2015In: 6th International Conference on Railway Operations Modelling and Analysis, Tokyo, Mars 23-26, 2015., 2015Conference paper (Refereed)
    Abstract [en]

    Maintaining high on-time performance and at the same time having high capacity utilization is a challenge for several railway traffic systems. The system becomes sensitive to disturbances and delays are easily propagating in the network. One way to handle this problem is to create more robust timetables; timetables that can absorb delays and prevent them from propagating. This paper presents an optimization approach to reduce the propagating of delays with a more efficient margin allocation in the timetable. A Mixed Integer Linear Programming (MILP) model is proposed in which the existing margin time is re-allocated to increase the robustness for an existing timetable. The model re-allocates both runtime margin time and headway margin time to increase the robustness at specific delay sensitive points in a timetable. We illustrate the model’s applicability for a real-world case where an initial, feasible timetable is modified to create new timetables with increased robustness. These new timetables are then evaluated and compared to the initial timetable. We evaluate how the MILP approach affects the initial timetable structure and its capability to handle disturbances by exposing the initial and the modified timetables to some minor initial disturbances of the range 1 up to 7 minutes. The results show that it is possible to reduce the delays by re-allocating margin time, for example, the total delay at end station decreases with 28 % in our real-world example.

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  • 4.
    Andersson, Emma
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Törnquist Krasemann, Johanna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Introducing a New Quantitative Measure of Railway Timetable Robustness Based on Critical Points2013In: 5th International Seminar on Railway Operations Modelling and Analysis - RailCopenhagen 2013, 2013Conference paper (Refereed)
    Abstract [en]

    The growing demand for railway capacity has led to high capacity consumption at times and a delay-sensitive network with insufficient robustness. The fundamental challenge is therefore to decide how to increase the robustness. To do so there is a need for accurate measures that return whether the timetable is robust or not and indicate where improvements should be made. Previously presented measures are useful when comparing different timetable candidates with respect to robustness, but less useful to decide where and how robustness should be inserted. In this paper, we focus on points where trains enter a line, or where trains are being overtaken, since we have observed that these points are critical for the robustness. The concept of critical points can be used in the practical timetabling process to identify weaknesses in a timetable and to provide suggestions for improvements. In order to quantitatively assess how crucial a critical point may be, we have defined the measure RCP (Robustness in Critical Points). A high RCP value is preferred, and it reflects a situation at which train dispatchers will have higher prospects of handling a conflict effectively. The number of critical points, the location pattern and the RCP values constitute an absolute value for the robustness of a certain train slot, as well as of a complete timetable. The concept of critical points and RCP can be seen as a contribution to the already defined robustness measures which combined can be used as guidelines for timetable constructors.

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    RailCopenhagen
  • 5.
    Andersson, Emma
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Törnquist Krasemann, Johanna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Robustness in Swedish Railway Traffic Timetables2011In: Railrome 2011: Book of Abstracts 4th International Seminar on Railway Operations Modelling and Analysis / [ed] S. Ricci, I.A. Hansen, G. Longo, D. Pacciarelli, J. Rodriguez, E. Wendler, 2011Conference paper (Other academic)
    Abstract [en]

    A tendency seen for quite some time in the Swedish railway network is a growing demand for capacity which no longer can be accommodated. This causes congestion and delays, and the relationships between the trains and how they affect eachother are significantly harder to overview and analyse. Railway traffic timetables normally contain margins to make them robust, and enable trains to recover from certain delays. How effective these margins are, depends on their size and location as well as the frequency and magnitude of the disturbances that occur. Hence, it is important to include marigns so, that they can be used operationally to recover from a variety of disturbances and not restricted to a specific part of the line and/or the timetable. In a case study we compare the performance of a selection of passenger train services to the different prerequisites given by the timetable (e.g. available margins and their location, critical train dependencies). The study focuses on the Swedish Southern mainline between Stockholm and Malmö on which a wide variety of train services operate, e.g. freight trains, local and regional commuter train services as well as long-distance trains with different speed profiles. The analysis shows a clear mismatch between where margins are placed and where delays occur. We also believe that the most widely used performance measure, which is related to the delay when arriving at the final destination, might give rise to an unnecessarily high delay rate at intermediate stations.

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  • 6.
    Andersson, Emma V.
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Törnquist Krasemann, Johanna
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology. Blekinge Institute of Technology, Department of Computer Science and Engineering, Karlskrona, Sweden .
    Quantifying railway timetable robustness in critical points2013In: Journal of Rail Transport Planning & Management, ISSN 2210-9706, E-ISSN 2210-9714, Vol. 3, no 3, p. 95-110Article in journal (Refereed)
    Abstract [en]

    Several European railway traffic networks experience high capacity consumption during large parts of the day resulting in delay-sensitive traffic system with insufficient robustness. One fundamental challenge is therefore to assess the robustness and find strategies to decrease the sensitivity to disruptions. Accurate robustness measures are needed to determine if a timetable is sufficiently robust and suggest where improvements should be made.

    Existing robustness measures are useful when comparing different timetables with respect to robustness. They are, however, not as useful for suggesting precisely where and how robustness should be increased. In this paper, we propose a new robustness measure that incorporates the concept of critical points. This concept can be used in the practical timetabling process to find weaknesses in a timetable and to provide suggestions for improvements. In order to quantitatively assess how crucial a critical point may be, we have defined the measure Robustness in Critical Points (RCP). In this paper, we present results from an experimental study where a benchmark of several measures as well as RCP has been done. The results demonstrate the relevance of the concept of critical points and RCP, and how it contributes to the set of already defined robustness measures.

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  • 7.
    Erlandson, William
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Keolis Sverige AB, Sweden.
    Häll, Carl Henrik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Meta-Heuristic for inserting a robust train path in a non-cyclic timetable2023In: Transportation planning and technology (Print), ISSN 0308-1060, E-ISSN 1029-0354, Vol. 46, no 7, p. 842-863Article in journal (Refereed)
    Abstract [en]

    Many freight trains depart Swedish marshalling yards before or after their planned departure times. Today, a deviating departure time is allowed if no conflicting train path can be found a few stations ahead. This increases the risk that the train might be delayed to its destination and cause delays to other trains. We present a meta-heuristic that modifies a timetable by adding a train path (for our freight train) and, if necessary, adjusting surrounding train paths. The aim of the insertion of the additional train path and the adjustments of the existing ones is to obtain a large bottleneck robustness, that is, the largest possible minimal temporal distance to any other train in the timetable. We provide experimental results for a Swedish railway stretch with a non-cyclic timetable and heterogeneous traffic. We show that we quickly add a train path, while improving the robustness of the timetable.

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  • 8.
    Erlandson, William
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Häll, Carl Henrik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Meta-Heuristic for Inserting a Robust Train Path in a Non-Cyclic Timetable2021Conference paper (Other academic)
  • 9.
    Fowler, Scott
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Hameseder, Katrin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    An Empirical Evaluation of Web System Access for Smartphone Clients2012In: Journal of Networks, E-ISSN 1796-2056, Vol. 7, no 11, p. 1700-1713Article in journal (Refereed)
    Abstract [en]

    As smartphone clients are restricted in computational power and bandwidth, it is important to minimise the overhead of transmitted messages.  This paper identifies and studies methods that reduce the amount of data being transferred via wireless links between a web service client and a web service. Measurements were performed in a real environment based on a web service prototype providing public transport information for the city of Hamburg in Germany, using actual wireless links with a mobile smartphone device.  REST based web services using the data exchange formats JSON, XML and Fast Infoset were evaluated against the existing SOAP based web service.

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  • 10.
    Gestrelius, Sara
    et al.
    SICS RISE AB, Kista, Sweden.
    Aronsson, Martin
    SICS RISE AB, Kista, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    A MILP-based heuristic for a commercial train timetabling problem2017In: 20th EURO Working Group on Transportation Meeting, EWGT 2017, 4-6 September 2017, Budapest, Hungary, Elsevier, 2017, Vol. 27, p. 569-576Conference paper (Refereed)
    Abstract [en]

    Using mathematical methods to support the yearly timetable planning process has many advantages. Unfortunately, the train timetabling problem for large geographical areas and many trains is intractable for optimization models alone. In this paper, we therefore present a MILP-based heuristic that has been designed to generate good-enough timetables for large geographical areas and many trains. In the incremental fix and release heuristic (IFRH), trains are added to the timetable in batches. For each batch of trains, a reduced timetable problem is solved using a mathematical integer program and CPLEX. Based on the solution, the binary variables defining meeting locations and stops are fixed, and the next batch of trains is added to the timetable. If previously fixed variables make the problem infeasible, a recovery algorithm iteratively releases fixed variables to regain feasibility. The paper also introduces a simple improvement heuristic (IH) that uses the same idea of working with batches of trains. The heuristics are tested on a real case-study from Sweden consisting of both small problem instances (approximately 300 trains and 1400 possible interactions) and large problem instances (approximately 600 trains and 5500 possible interactions). IFRH returns a feasible timetable within 30 minutes for all problem instances, and after running IH the optimality gaps are less than 5%. Meanwhile, if CPLEX is used without the heuristic framework to solve the total optimization problem, a feasible timetable is not returned within 2 hours for the large problem instances.

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  • 11.
    Gestrelius, Sara
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Mobility and Systems, Research Institutes of Sweden.
    Häll, Carl Henrik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Capacity Utilization, Travel Time, Stability and Heterogeneity - a Linear Programming Analysis for Railway Timetabling2021Conference paper (Refereed)
  • 12.
    Gestrelius, Sara
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. RISE, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Aronsson, Martin
    RISE, Sweden.
    Tidtabellskvalitet (TTK): Teknisk Slutrapport2020Report (Other academic)
    Abstract [sv]

    KAJT projektet TTK (Tidtabellskvalitet) var ett treårigt projekt som syftade till att ta fram ett ramverk som mäter en tidtabells kvalitet. Effektmålet är bättre balanserade och därmed mer kvalitativa tidtabeller.

    I den här slutrapporten presenteras de resultat som togs fram under projektet. Det är dels texter baserade på litteraturstudier (kapitel 5 och delar av kapitel 7), ochs dels rapportering av resultat från workshoppar, en intervjustudie (kapitel 6) och den första implementation av ramverket (kapitel 7).

    Projektet undersökte kvalitetsmått för fem kvalitetsaspekter: teoretisk körbarhet, robusthet och återställningsförmåga, konkurrenshantering, reservkapacitet och ansökningsuppfyllnad. Fyra slutsatser från projektet är att:

    1. I dagens process finns det skrivna regler för teoretisk körbarhet, robusthet och tvistlösning. Övriga kvalitetsaspekter saknas det tydliga regler för, och det saknas helt stöd för att kunna väga olika kvalitetsaspekter mot varandra.
    2. Det saknas forskning på kvalitetsmått för vissa kvalitetsaspekter. När det kommer till trafik så saknas specifikt publicerade mått för reservkapacitet och konkurrenshantering, trots att dessa aspekter lyfts fram i både svensk och europeisk lagstiftning. För att kunna designa ett fullvärdigt ramverk för flermålsoptimering krävs kvalitetsmått även för dessa aspekter.
    3. I dagens planeringsprocess bedöms aspekterna teoretisk körbarhet och robusthet som viktiga. Minst viktig bedöms reservkapacitet vara. Däremot upplevs reservkapacitet som absolut svårast att jobba med.
    4. Ramverket som projektet tog fram har testats på Värmlandsbanan. Kvalitetsmätningar genomfördes för andra torsdagen i oktober för 2014-2018. I dess mätningar syns en förbättring för ett flertal mått mellan 2016 och 2017 års tidtabeller, vilket är förväntat då nya konstruktionsregler infördes 2017. Ramverket med flermålsoptimering testades på andra torsdagen i oktober 2018. Tre styrpunkter användes för att ta fram tre olika tidtabeller, varav ingen dominerar de andra. Resultatet visar att det, i alla fall i enskilda trafikdagar, finns utrymme för att generera olika pareto-optimala tidtabeller. Det vill säga, givet att man inte i förväg kan bestämma sig för vilka kvalitetsmått som är viktigast, så kan man generera ett antal tidtabeller där ingen är absolut bättre än de andra.
    5. Viktiga framtida forskningsområden är (1) att identifiera och implementera mätvärden för banarbeten i kvalitetsramverket, (2) att ta fram kvalitetsmått för de aspekter där sådana saknas, (3) att ta fram metoder för att säkerställa att tåglägen som går över flera konstruktionsområden är av god kvalitet (4) att ta fram en metod för att hantera gapet mellan teori och praktik samt (5) att undersöka olika kvalitetsmåtts effektivitet.

    Vidare rekommenderar vi att Trafikverket undersöker möjligheterna för att ta fram riktlinjer även för de kvalitetsaspekter som inte är teoretisk körbarhet och robusthet, samt utvecklar processer och stödverktyg som hjälper tidtabellsplanerare väga olika kvalitetsaspekter mot varandra.

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  • 13.
    Gestrelius, Sara
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. RISE Res Inst Sweden, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Aronsson, Martin
    RISE Res Inst Sweden, Sweden.
    Timetable quality from the perspective of a railway infrastructure manager in a deregulated market: An interview study with Swedish practitioners2020In: Journal of Rail Transport Planning & Management, ISSN 2210-9706, E-ISSN 2210-9714, Vol. 15, article id 100202Article in journal (Refereed)
    Abstract [en]

    Railway capacity allocation in a deregulated market requires planners to solve a mathematically complex optimization problem while simultaneously arbitrating the wants and needs of different stakeholders. This paper analyses timetable quality from the perspective of timetable planners working for the Swedish infrastructure manager Trafikverket. Seven quality aspects are discussed: feasibility, disturbance resistance, competition management, capacity safeguarding, application fulfilment, attractiveness and compatibility with surrounding planning areas. Each aspect is introduced, including references to legal documents, development projects, and research literature. Further, an interview study with eight practitioners gives insight into the current state of practice in Sweden. The practitioners consider feasibility to be both most important and easiest to handle. Capacity safeguarding is considered least important, despite its prevalence in legal documents and envisioned process developments, and is also considered hardest to handle. In general, formal rules and guidelines seem important for emphasising the importance of a quality aspect in the planning process. To better support the planners in their arbitrating role, timetable planning tools based on mathematical optimization models could be implemented. For example, support tools could be used to analyse different solutions, and could unburden the planner from working with feasibility aspects by providing automatic conflict identification and resolution.

  • 14.
    Hameseder, Katrin
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Fowler, Scott
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Performance Analysis of Ubiquitous Web Systems for SmartPhones2011In: Proceedings of the 2011International Symposium onPerformance Evaluation of Computerand Telecommunication Systems / [ed] Mohammad S., Obaidat José L., Sevillano, Pere Vilá, Isaac Woungang, Raffaele Bolla, Daniel Cascado, IEEE , 2011, p. 84-89Conference paper (Refereed)
    Abstract [en]

    As smartphone clients are restricted in computational power and bandwidth it is important to minimise the overhead of transmitted messages and since it results in processing time when implementing a web service. This paper identifies and studies methods that reduce the amount of data being transferred via wireless links between a Web service client and a Web service. The goal is to improve the end-to-end service execution time by reducing the bottleneck presented by the limited bandwidth in an ubiquitous environment. Measurements are performed in a real environment based on a web service prototype providing public transport information for the city of Hamburg in Germany, using actual wireless links with a mobile smartphone device. The existing SOAP based web service is evaluated against a REST based web service using the data exchange formats JSON, XML and Fast Infoset.

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  • 15.
    Häll, Carl Henrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Lundgren, Jan T.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Improving the efficiency of swedish paratransit: an application of the dial-a-ride problem2009Conference paper (Other academic)
  • 16.
    Häll, Carl Henrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Improving paratransit scheduling using ruin and recreate methods2013In: Transportation planning and technology (Print), ISSN 0308-1060, E-ISSN 1029-0354, Vol. 36, no 4, p. 377-393Article in journal (Refereed)
    Abstract [en]

    In this paper we study the effects of using ruin and recreate methods in a replanning phase of a dynamic dial-a-ride problem. Several such methods are proposed, and a modeling system is used to evaluate how they improve the quality of the solutions. We show that simple changes to existing planning methods can increase the efficiency of the service. Two cases, with different forms of costs inflicted on the vehicles, are evaluated and significant improvements are found in both cases. The best results of our study are found with ruin methods based on removal of sequences of requests.

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  • 17.
    Johansson, Fredrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Tapani, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Local performance measures of pedestrian traffic2014In: Public Transport, ISSN 1866-749X, E-ISSN 1613-7159, Vol. 6, no 1-2, p. 159-183Article in journal (Refereed)
    Abstract [en]

    Efficient interchange stations, where travelers are changing lines and/or travel modes, are essential for the functionality of the whole public transport system. By studying pedestrian movements, the level of service and effectiveness imposed by the design of the interchange station can be evaluated. We address the problem by microsimulation, where a social force model is used for the phenomenological description of pedestrian interactions. The contribution of this paper is the proposal of measures describing the density, delay, acceleration and discomfort for pedestrian flows. Simulation experiments are performed for the movements in two canonical pedestrian areas, a corridor and a corridor intersection. Clearly, each of the four measures gives a description for how pedestrians impede each other, and hence for the efficiency at the facility. There is, however, different information provided by each measure, and we conclude that they all are well-motivated for quantifying the level of service in a pedestrian flow. We also illustrate the outcome for a railway platform, with two trains arriving in parallel.

  • 18.
    Johansson, Fredrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Tapani, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Performance evaluation of railway platform design using microscopic simulation2012Conference paper (Other academic)
    Abstract [en]

    Efficient interchange stations, where travelers are changing lines and/or travel modes, are essential for the functionality of the whole public transport system. By studying pedestrian movements, the level of service and effectiveness imposed by the design of the interchange station can be evaluated.

    We address the problem by microsimulation, where a social force model is used for the phenomenological description of pedestrian interactions. The contribution of this paper is the proposal of measures describing the density, delay, acceleration and discomfort for pedestrian flows.

    Simulation experiments are performed for the movements in two canonical pedestrian areas, a corridor and a corridor intersection. Clearly, each of the four measures gives a description for how pedestrians impede each other, and hence for the efficiency at the facility. There is, however, different information provided by each measure, and we conclude that they all are well-motivated for quantifying the level of service in a pedestrian flow. We also illustrate the outcome for a railway platform, with two trains arriving in parallel.

  • 19.
    Johansson, Fredrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology. Swedish National Rd and Transport Research Institute VTI, SE-58195 Linkoping, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Tapani, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology. Swedish National Rd and Transport Research Institute VTI, SE-58195 Linkoping, Sweden.
    Waiting pedestrians in the social force model2015In: Physica A: Statistical Mechanics and its Applications, ISSN 0378-4371, E-ISSN 1873-2119, Vol. 419, p. 95-107Article in journal (Refereed)
    Abstract [en]

    Microscopic simulation of pedestrian traffic is an important and increasingly popular method to evaluate the performance of existing or proposed infrastructure. The social force model is a common model in simulations, describing the dynamics of pedestrian crowds given the goals of the simulated pedestrians encoded as their preferred velocities. The main focus of the literature has so far been how to choose the preferred velocities to produce realistic dynamic route choices for pedestrians moving through congested infrastructure. However, limited attention has been given the problem of choosing the preferred velocity to produce other behaviors, such as waiting, commonly occurring at, e.g., public transport interchange stations. We hypothesize that: (1) the inclusion of waiting pedestrians in a simulated scenario will significantly affect the level of service for passing pedestrians, and (2) the details of the waiting model affect the predicted level of service, that is, it is important to choose an appropriate model of waiting. We show that the treatment of waiting pedestrians have a significant impact on simulations of pedestrian traffic. We do this by introducing a series of extensions to the social force model to produce waiting behavior, and provide predictions of the model extensions that highlight their differences. We also present a sensitivity analysis and provide sufficient criteria for stability. (C) 2014 Elsevier B.V. All rights reserved.

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  • 20.
    Johansson, Ingrid
    et al.
    KTH, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Rail platform allocation for reliable interchanges2024In: EWGT 2023 Conference Proceedings, Elsevier, 2024, Vol. 78, p. 198-205Conference paper (Refereed)
    Abstract [en]

    Changing trains is a crucial part of many rail journeys, and it is important that arrival and departing trains are allocated close to each other for a swift interchange. Today the platform allocation of trains is often based on local traditions, where trains of the same type to the same destination depart from the same track. In this paper we address the problem of using the platform tracks in the best way, balancing crossing train paths with easy interchanges at the same platform. We use a RailSys model of the station in Norrköping, Sweden, to assess three platform allocation strategies with respect to crossing train paths and train changes at the same platform. Moreover, the capacity utilisation is calculated by a timetable compression-based method. The results show that a platform allocation maximising the changes at the same platform leads to more crossing train paths and higher capacity utilisation. Future work includes more accurate modelling of train connections, assessment of delays through simulation, and a cost-benefit analysis to find the best balance between easy interchanges and conflicting train paths.

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  • 21.
    Johansson, Ingrid
    et al.
    KTH, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Rail platform allocation for reliable interchanges2024In: EWGT 2023 Conference Proceedings, Elsevier, 2024, p. 198-205Conference paper (Refereed)
    Abstract [en]

    Changing trains is a crucial part of many rail journeys, and it is important that arrival and departing trains are allocated close to each other for a swift interchange. Today the platform allocation of trains is often based on local traditions, where trains of the same type to the same destination depart from the same track. In this paper we address the problem of using the platform tracks in the best way, balancing crossing train paths with easy interchanges at the same platform. We use a RailSys model of the station in Norrköping, Sweden, to assess three platform allocation strategies with respect to crossing train paths and train changes at the same platform. Moreover, the capacity utilisation is calculated by a timetable compression-based method. The results show that a platform allocation maximising the changes at the same platform leads to more crossing train paths and higher capacity utilisation. Future work includes more accurate modelling of train connections, assessment of delays through simulation, and a cost-benefit analysis to find the best balance between easy interchanges and conflicting train paths.

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  • 22.
    Kecman, Pavle
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Corman, Francesco
    Delft University of Technology, The Netherlands.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Joborn, Martin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Stochastic prediction of train delays in real-time using Bayesian networks2015In: Conference on Advanced Systems in Public Transport: CASPT2015, ETH Zurich, 2015Conference paper (Refereed)
    Abstract [en]

    In this paper we present a stochastic model for predicting the propagation of train delays based on Bayesian networks. This method can eciently represent and compute the complex stochastic inference between random variables. Moreover, it allows updating the probability distributions and reducing the uncertainty of future train delays in real time under the assumption that more information continuously becomes available from the monitoring system. The dynamics of a train delay over time and space is presented as a stochastic process that describes the evolution of the time-dependent random variable. This approach is further extended by modelling the interdependence between trains that share the same infrastructure of have a scheduled passenger transfer. The model is applied on a set of historical trac realisation data from the part of a busy corridor in Sweden.We present the initial results and analyse the accuracy of predictions as well as the evolution of probability distributions of event delays over time. The presented method is important for making better predictions for train trac, that are not only based on static, oine collected data, but are able to positively include the dynamic characteristics of the continuously changing delays.

  • 23.
    Khoshniyat, Fahimeh
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Improving Train Service Reliability by Applying an Effective Timetable Robsutness Strategy2017In: Journal of Intelligent Transportation Systems / Taylor & Francis, ISSN 1547-2450, E-ISSN 1547-2442, Vol. 21, no 6, p. 525-543Article in journal (Refereed)
    Abstract [en]

    To avoid propagation of delays in dense railway timetables, it is important to ensure robustness. One strategy to improve robustness is to provide adequate amount of buffer times between trains. This study concerns how “scheduled minimum headways” should be determined in order to improve robustness in timetables. Scheduled minimum headways include technical minimum headway plus some buffer time. We propose a strategy to be implemented in timetables at the final stages of planning and prior to the operations.  The main contributions of this study are 1) to propose a strategy where the size of the scheduled minimum headways is dependent on trains' travel times instead of a fixed-sized time slot and it is called “travel time dependent scheduled minimum headways” or TTDSMH, 2) to evaluate the effects of the new strategy on heterogeneity, speed, and the number of trains in timetables, 3) to show that a simple strategy can improve robustness without imposing major changes in timetables. The strategy is implemented in an Mixed Integer Linear Programming framework for timetabling and tested for some problem instances from Sweden. Results show that TTDSMH can improve robustness. The proposed strategy can be applied in intelligent transportation tools for railway timetabling.

  • 24.
    Khoshniyat, Fahimeh
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Robustness Improvements in a Train Timetable with Travel Time Dependent Minimum Headways2015Conference paper (Other academic)
    Abstract [en]

    In a railway network with dense traffic, trains’ scheduled arrival and departure times arehighly dependent on each other and even a small delay easily propagates to subsequenttrains using the same infrastructure resources. In the current paper a given timetable is comparedto a modified timetable, where the assigned minimum time slot in the traffic for aservice is linearly increasing with the service’s travel time. The underlying assumption isthat trains lose precision as they travel longer and catching a fixed-size time slot is easier atthe beginning of the journey. Real world observations confirm this assumption as well. Theaim of this study is to verify the improvement in the robustness of those timetables that aremodified with respect to the idea of travel time dependent reserved time slots for the arrivaltimes of trains and to compare the results with the initial timetables. Numerical experimentsare conducted on a selected double track segment of the Swedish Southern mainline. Fourtimetable case studies are considered for the experiments: off-peak hours and peak hoursin 2011 and 2014, respectively. Each timetable is tested for various disturbance scenarios.Several performance measures are used to evaluate delay propagation in the timetables, includingdeviations from the initial timetable, total delays, total number of delayed trains atdestinations, number of punctual trains with 5 minutes arrival delay tolerance at destinationsand number of violations in trains’ overtaking orders. Results show that the modifiedtimetables outperform the initial ones for small disturbances.

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  • 25.
    Larsson, Torbjörn
    et al.
    Linköping University, Department of Mathematics, Optimization . Linköping University, The Institute of Technology.
    Lundgren, Jan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Peterson, Anders
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Allocation of Link Flow Detectors for Origin-Destination Matrix Estimation-A Comparative Study2010In: COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, ISSN 1093-9687, Vol. 25, no 2, p. 116-131Article in journal (Refereed)
    Abstract [en]

    Origin-destination (OD) matrices are essential for various analyses in the field of traffic planning, and they are often estimated from link flow observations. We compare methods for allocating link flow detectors to a traffic network with respect to the quality of the estimated OD-matrix. First, an overview of allocation methods proposed in the literature is presented. Second, we construct a controlled experimental environment where any allocation method can be evaluated, and compared to others, in terms of the quality of the estimated OD-matrix. Third, this environment is used to evaluate and compare three fundamental allocation methods. Studies are made on the Sioux Falls network and on a network modeling the city of Linkoping. Our conclusion is, that the most commonly studied approach for detector allocation, maximizing the coverage of OD-pairs, seems to be unfavorable for the quality of the estimated OD-matrix.

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  • 26.
    Licciardello, Riccardo
    et al.
    SAPIENZA Università di Roma, Dipartimento di Ingegneria Civile, Edile e Ambientale (DICEA), Roma, Italia.
    Adamko, Norbert
    University of Zilina, Slovak Republic.
    Deleplanque, Samuel
    Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, Yncréa Hauts-de-France, UMR 8520 - IEMN, France.
    Hosteins, Pierre
    COSYS-ESTAS, Univ Gustave Eiffel, IFSTTAR, Univ Lille, Villeneuve d’Ascq, France.
    Liu, Ronghui
    University of Leeds, Institute for Transport Studies (ITS), Leeds, United Kingdom.
    Pellegrini, Paola
    COSYS-LEOST, Univ Gustave Eiffel, IFSTTAR, UnivLille, Villeneuve d’Ascq, France.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Wahlborg, Magnus
    Swedish Transport Administration, Borlänge, Sweden.
    Zatko, Miloš
    Simcon s.r.o., Zilina, Slovak Republic.
    Integrating yards, network and optimisation models towards real-time rail freight yard operations2020In: Ingegneria Ferroviaria, ISSN 0020-0956, Vol. 6, p. 417-440Article in journal (Refereed)
    Abstract [en]

    This paper describes the state of advancement achieved in the OptiYard research project in the use of optimisation algorithms in interaction with microsimulation of the rail-yard and surrounding network towards realtime yard management and communication with the network. Two case studies, a hump marshalling yard (mainly Single Wagon Load traffic) and a flat shunting yard (mainly intermodal traffic), were represented with state-of-the art microsimulation models, combined with innovative optimisation algorithms. Some specialistic information on the nature of the models is provided. However, the focus is oriented to railway engineers, with a description of the interactions between the models in producing outputs that are useful both to the yard dispatcher (decisions on staff, track, locomotive assignment, order of operations) and the infrastructure manager of the surrounding network (expected times of departure, availability of tracks in the yard).

  • 27.
    Lindberg, Therese
    et al.
    Swedish Natl Rd & Transport Res Inst VTI, S-58195 Linkoping, Sweden.
    Johansso, Fredrik
    Swedish Natl Rd & Transport Res Inst VTI, S-58195 Linkoping, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Tapani, Andreas
    Swedish Transport Agcy, Sweden.
    MICROSIMULATION OF BUS TERMINALS: A CASE STUDY FROM STOCKHOLM2020In: 2020 WINTER SIMULATION CONFERENCE (WSC), IEEE , 2020, p. 1206-1217Conference paper (Refereed)
    Abstract [en]

    When new bus terminals are being planned or existing ones redesigned, suitable tools that are able to describe the complex situation at a terminal are needed. Using microsimulation, vehicle movements and interactions can be simulated and the congestion and capacity of a terminal can be evaluated. In this study, a discrete event simulation model is used in a case study of the Slussen bus terminal in Stockholm, Sweden. The model is calibrated and validated with empirical data that are automatically collected at the terminal. Already with this limited amount of data, the parameter time per boarding passenger can be calibrated with a relative error less than 1 % and the validation gives further insights into the data needed for calibration of a terminal simulation model.

  • 28.
    Lindberg, Therese
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Statens väg- och transportforskningsinstitut.
    Johansson, Fredrik
    Statens väg- och transportforskningsinstitut.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    An integer optimization model for allocation of bus lines to the stops of a bus terminal2022Conference paper (Refereed)
    Abstract [en]

    Interchange stations are essential for a high-quality public transport system. Many passengers pass through a station during the course of a day and the time spent at a station has a large effect on their experience of the whole journey. In this study, we aim to improve the passenger experience at a bus terminal by minimizing the walking distances for all passengers. To this end, an integer linear optimization model which allocates bus lines to the stops of a bus terminal is presented. The model is tested in a numerical experiment using synthetic passenger data. Two alternative approaches, either randomly allocated or based on the number of non-transferring passengers, are used for comparisons. The average improvement in relation to the random allocation strategy is 13%, which shows that the allocation approach has potential. It is thus of interest to collect data from a real bus terminal to further explore the model and the potential benefits it can provide.

  • 29.
    Lindberg, Therese
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. VTI, Swedish Natl Rd & Transport Res Inst, S-58195 Linkoping, Sweden; K2 Swedish Knowledge Ctr Publ Transport, Sweden.
    Johansson, Fredrik
    VTI, Swedish Natl Rd & Transport Res Inst, S-58195 Linkoping, Sweden; K2 Swedish Knowledge Ctr Publ Transport, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Tapani, Andreas
    Swedish Transport Agcy, Sweden.
    Discrete Event Simulation of Bus Terminals: A Modular Approach with a High Spatial Resolution2021In: Journal of Advanced Transportation, ISSN 0197-6729, E-ISSN 2042-3195, Vol. 2021, article id 8862893Article in journal (Refereed)
    Abstract [en]

    Interchange stations with their many connecting modes and lines are central for a high-quality public transport system. Bus access at the station needs to operate reliably and efficiently in order to prevent congestion and queues. To this end, a conceptual simulation model for evaluation of bus terminal operations is presented in this paper. It is based on discrete event simulation and able to describe the detailed movements and interactions that occur between vehicles at larger terminals. The model has a modular approach, where common spatial sections at terminals are represented by modules that can be easily combined into many different terminal layouts. An implementation of the model is presented and, as a first sensitivity test, applied in a numerical experiment representing Norrkoping interchange station in Sweden. The results indicate that the model can be a useful tool in planning processes.

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  • 30.
    Lindberg, Therese
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. VTI, Linköping, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Tapani, Andreas
    VTI, Linköping, Sweden.
    A simulation model for assessment and evaluation of busterminal design2018Conference paper (Other academic)
    Abstract [en]

    Interchange stations with their connections between modes and lines are central for a high quality public transport system. Bus access at the station needs to operate reliably and efficiently in order to prevent congestion and queues. Here, a discrete event simulation model of vehicle movements and interactions at bus terminals is developed and implemented. The model has a modular approach, where common spatial sections at terminals are represented by modules that can be combined into various terminal layouts. These modules describe the events a vehicle may go through in a particular section of the terminal, such as arriving to a bus stop or stopping at a traffic light at the exit. The model can be used in planning processes, both for new terminals and redesign of existing ones, and is able to describe the detailed movements and interactions between vehicles that occur at larger terminals. The model is tested in a numerical experiment representing Norrköping interchange station in Sweden. The experiment shows that the model is able to evaluate and compare different scenarios and can thus be a useful tool in planning processes.

  • 31.
    Lindberg, Therese
    et al.
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering. VTI, Swedish National Road and Transport Research Institute, Linköping, Sweden; K2 - The Swedish Knowledge Center for Public Transport, Lund, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Tapani, Andreas
    VTI, Swedish National Road and Transport Research Institute, Linköping, Sweden; K2 - The Swedish Knowledge Center for Public Transport, Lund, Sweden.
    A Simulation Model of Local Public Transport Access at a Railway Station2017In: Proceedings of Raillille 2017 - 7th lnternational Conference on Railway Operations Modelling and Analysis / [ed] N. Tomii, I.A. Hansen, J. Rodriguez, P. Pellegrini, S. Dauzère-Pérès, D. De Almeida, 2017, p. 922-943Conference paper (Other academic)
    Abstract [en]

    A high quality railway service requires that all parts of the complete journey, from door to door, are well-functioning. This includes any transfers taking place, as well as last mile transportation to and from the railway station. Since the last mile often consists of local public transport, the access to this mode at stops and terminals and how well these are functioning are of great importance. A critical aspect is the capacity of the stop or the terminal in relation to the number of departures, where a higher capacity generally means an increase in size. At the same time it is desirable to limit the use of valuable land and keeping the facility as small as possible. The trade-off between capacity and size needs to be evaluated when designing stops and terminals. In this study we have developed a discrete event simulation model of a combined bus and tram stop, which is a part of a larger multi-modal station. The objective of the study is to evaluate the modelling approach for the situation at hand. Of special interest are the complexities due to the different driving patterns of buses and trams. The developed model is capable of evaluating design alternatives and is applied in a case study of a stop at Norrköping railway station in southern Sweden. The model was found to realistically capture the various events occurring at such a stop and the case study further showed that the model is a useful tool in design evaluation.

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  • 32.
    Ljunggren, Fredrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Trafikverket.
    Persson, Kristian
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Sweco.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Maximum Robust Train Path for an Additional Train Inserted in an Existing Railway Timetable2018Conference paper (Other academic)
    Abstract [en]

    We present an algorithm to insert a train path in an existing railway timetable close to operation, when we want to affect the existing (passenger) traffic as little as possible. Thus, we consider all other trains as fixed, and aim for a resulting train path that maximizes the bottleneck robustness. Our algorithm is based on a graph formulation of the problem and uses a variant of Dijkstra's algorithm.

    We present an extensive experimental evaluation of our algorithm for the Swedish railway stretch from Malmö to Hallsberg. Moreover, we analyze the size of our constructed graph.

  • 33.
    Ljunggren, Fredrik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Persson, Kristian
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Railway timetabling: a maximum bottleneck path algorithm for finding an additional train path2021In: Public Transport, ISSN 1866-749X, E-ISSN 1613-7159, Vol. 13, p. 597-623Article in journal (Refereed)
    Abstract [en]

    We present an algorithm to insert a train path in an existing railway timetable close to operation, when we want to affect the existing (passenger) traffic as little as possible. Thus, we consider all other trains as fixed, and aim for a resulting train path that maximizes the bottleneck robustness, that is, a train path that maximizes the temporal distance to neighboring trains in the timetable. Our algorithm is based on a graph formulation of the problem and uses a variant of Dijkstra’s algorithm. We present an extensive experimental evaluation of our algorithm for the Swedish railway stretch from Malmö to Hallsberg. Moreover, we analyze the size of our constructed graph.

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  • 34.
    Lundgren, Jan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem2008In: Transportation Research Part B: Methodological, ISSN 0191-2615, E-ISSN 1879-2367, Vol. 42, no 4, p. 339-354Article in journal (Refereed)
    Abstract [en]

    In this paper we consider the estimation of an origin–destination (OD) matrix, given a target OD-matrix and traffic counts on a subset of the links in the network. We use a general nonlinear bilevel minimization formulation of the problem, where the lower level problem is to assign a given OD-matrix onto the network according to the user equilibrium principle. After reformulating the problem to a single level problem, the objective function includes implicitly given link flow variables, corresponding to the given OD-matrix. We propose a descent heuristic to solve the problem, which is an adaptation of the wellknown projected gradient method. In order to compute a search direction we have to approximate the Jacobian matrix representing the derivatives of the link flows with respect to a change in the OD-flows, and we propose to do this by solving a set of quadratic programs with linear constraints only. If the objective function is differentiable at the current point, the Jacobian is exact and we obtain a gradient. Numerical experiments are presented which indicate that the solution approach can be applied in practice to medium to large size networks.

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  • 35.
    Lundgren, Jan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Rydergren, Clas
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    A heuristic for the estimation of time-dependent origin-destination matrices from traffic counts2005In: Advanded OR an AI Methods in Transportation, Proceedings of the 10th Jubilee Meeting of the EURO Working Group on Transportation,2005, Poznan, Poland: Publishing House of Poznan University of Technology , 2005, p. 242-Conference paper (Refereed)
  • 36.
    Lundgren, Jan T.
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Rydergren, Clas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    A Heuristic for the Estimation of Time-Dependent Origin Origin–Destination Matrices from Traffic Counts2007In: Nordic MPS ’04, Norrköping, Sweden, October 21–23, 2004 and The 10th Jubilee Meeting of the EURO Working Group on Transportation, Poznan, Poland, September 13–16, 2005 and Transportforum, Linköping, Sweden, January 11–12, 2006, 2007Conference paper (Refereed)
  • 37.
    Lundgren, Jan T.
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Tengroth, Stellan
    Vägverket Region Väst, Swedish National Road Administration.
    Methods for Pre-Adjusting Time-Dependent Origin–Destination Matrices: an Application to Gothenburg2003In: Proceedings of the 10th World Congress and Exhibition on Intelligent Transport Systems and Services, Madrid, Spain, November 16–20, 2003, no 2436Conference paper (Refereed)
    Abstract [en]

    We present a number of schemes for adjusting time-dependent travel demand information with respect to link flow observations. The aim is to utilize the structure of the given OD-matrix, which is compounded from different sources, for making simple overall adjustments. These pre-adjustments are then followed up with a complete OD-estimation procedure, such as that in Contram. Numerical results from the city of Gothenburg are presented.

  • 38.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Wahlborg, Magnus (Contributor)
    Swedish Transport Administration, Sweden.
    Kecman, Pavle (Contributor)
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Ringdahl, Rasmus (Contributor)
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Kroča, Petr (Contributor)
    Research and Innovation, OLTIS Group, Česká republika.
    Nelldal, Bo-Lennart Nelldal (Contributor)
    Royal Institute of Technology, KTH, Stockholm, Sweden.
    Solinen, Emma (Contributor)
    Swedish Transport Administration, Sweden.
    Nicholson, Gemma (Contributor)
    Birmingham Centre for Railway Research and Education, University of Birmingham, Birmingham, UK.
    Deliverable 32.2: Capacity impacts of innovations2017Report (Other academic)
    Abstract [en]

    Deliverable D32.2 “Capacity impacts of innovations” summarizes the results of the Capacity 4 Rail work package WP3.2 “Simulation and models to evaluate enhanced capacity (infrastructure and operation)”. Capacity in the railway system can be divided in strategic level (planning of infrastructure), tactical level (timetabling) and operational level (dispatching). Closely related to the operational planning are Driver Advisory Systems (DAS), which in the future may be extended towards fully automatized driving.

    At strategic level an analysis have been made about line capacity and train capacity for future rail freight corridors. The analysis shows how to increase capacity for future freight trains 2030/2050, by extending the train capacity well as the line capacity and the combination of train and line capacity for futures scenarios.

    In the future, the processes for tactical and operational planning are merging, meaning that the timetable is no longer a static, or annually updated, product, but a working document that is improved successively, until handed over to operational management. Also in the operational management, we believe that control by planning is a good strategy. Processes for capacity and timetable planning, as well as timetable and traffic simulation systems are under development. The amount of available data is increasing.

    The main research results of Capaciyt 4Rail SP 3.2 have been:

    1. A model framework for modelling and planning of demand and supply of capacity at various levels with micro simulation, data analysis and optimisation. By combining these methods especially tactical and operational planning and control can be improved, and hence, enabling more trains and/or increased on-time performance.

    2. A statistical model (LiU model) to forecast delay propagation. The model relies on the theory of Bayesian networks, and can be used both for planning and informing.

    3. A demonstrator, CAIN, an extension to the KADR system for timetable and operational traffic developed by Oltis group Czech. The CAIN tool is connected to the LiU model and relies on data from Railsys (micro level infrastructure, complete tracklayout modelled) and Trafikverket database of disturbances and delays Lupp. The demonstrator has been set-up for Malmö – Hallsberg, a part of the Scandinavian Mediterranean corridor TEN-T network. It has given us new knowledge about interaction between IM timetable system and optimisation/data analysis model to predict timetable robustness and punctuality in the network due to changes in the timetable.

    4. A separate analysis of space–time points in the timetable critical for robustness. The study of critical points in this project has given knowledge about how to use the method when data is known at micro level, represented by RailSys. The improved robustness is also set in relation to other key performance indicators.

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  • 39.
    Peterson, Anders
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Origin-destination matrix estimation from traffic counts2003Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    For most kind of analyses in the field of traffic modeling, there is a need for origin-destination (OD) matrices, which specify the travel demands between the origin and destination nodes in the network. The process of obtaining OD-matrices is long, complicated and expensive. The counting of traffic, which provides link flow observations, therefore is an opportune possibility for easily up-dating the information on the travel demand. This thesis concerns the estimation of OD-matrices from traffic counts. 

    We will consider the problem to estimate OD-matrices for both time-indepenent and time-dependent models. Many models have been suggested for the time-independent case, where the quantities represent and average situation. If a user equilibrium is assumed for the link flows in the network, a bilevel problem structure is recognized, where the link flows are implicitly expressed as a traffic assignment of the present OD-matrix. A descent heuristic, which is an adaptation of the well-known projected gradient method, is proposed. Special attention is given to the problem of approximating the Jacobian matrix, which expresses the change of a certain link flow with respect to a unit change of the travel demand in a certain pair of origin and destination.

    When a time dimension is introduced, the estimation problem becomes more complex. Besides the problem of distributing the travel demand onto different routes, the flow propagation with respect to time must be handled. A general time-dependent extension of the estimation problem is given and the complications with dynamic traffic assignment are discussed. In a case study, the conventional solution technique is improved by introducing pre-adjustment schemes, which the structure of the information provided by the OD-matrix and the link flow observations.

    List of papers
    1. Traffic Demand Modeling and Origin-Destination Matrix Estimation
    Open this publication in new window or tab >>Traffic Demand Modeling and Origin-Destination Matrix Estimation
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    An origin-destination (OD) matrix describes the travel demand between all pairs of origins and destinations in a traffic network. OD-matrices are essential input for most types traffic models, both for long-term planning, where the actions are meant to be permanent, and for short-term planning, where the operational situation is managed. This paper is a literature overview of models and methods for obtaining reliable OD-matrices.

    We present the Four-stage model which is commonly used for sequentially computing the number of trips starting and terminating at the centroid nodes, the distribution to travel demand between origins and destinations, the split onto different travel modes and the choice-based assignment of routes and links in the network. Further, we identify the information contained in traffic counts as an important source for adjusting the computed OD-matrix. The generic OD-matrix estimation problem from link flow observations is formulated and we discuss different solution techniques and how they relate to the assumptions used for the assignment of travel demand to routes and links.

    Time-dependence is a fundamental difference between the model types. A time-independent (static) model describes a steady state, which represents and average situation. If the interaction between sequential time periods is to be analyzed, however, a dynamic model is required. The time dimension is a complicating factor, since not only the route choice, but also the flow propagation must be taken care of in the model. Especially those models where the OD-matrix is to be estimated in real-time, must be simplified as to the computational effort.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-102432 (URN)
    Available from: 2013-12-10 Created: 2013-12-10 Last updated: 2018-08-23
    2. A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem
    Open this publication in new window or tab >>A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem
    2008 (English)In: Transportation Research Part B: Methodological, ISSN 0191-2615, E-ISSN 1879-2367, Vol. 42, no 4, p. 339-354Article in journal (Refereed) Published
    Abstract [en]

    In this paper we consider the estimation of an origin–destination (OD) matrix, given a target OD-matrix and traffic counts on a subset of the links in the network. We use a general nonlinear bilevel minimization formulation of the problem, where the lower level problem is to assign a given OD-matrix onto the network according to the user equilibrium principle. After reformulating the problem to a single level problem, the objective function includes implicitly given link flow variables, corresponding to the given OD-matrix. We propose a descent heuristic to solve the problem, which is an adaptation of the wellknown projected gradient method. In order to compute a search direction we have to approximate the Jacobian matrix representing the derivatives of the link flows with respect to a change in the OD-flows, and we propose to do this by solving a set of quadratic programs with linear constraints only. If the objective function is differentiable at the current point, the Jacobian is exact and we obtain a gradient. Numerical experiments are presented which indicate that the solution approach can be applied in practice to medium to large size networks.

    Place, publisher, year, edition, pages
    Institutionen för teknik och naturvetenskap, 2008
    Keywords
    Origin-Destination matrix; Sensitivity analysis; User-equilibrium
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-11461 (URN)10.1016/j.trb.2007.09.005 (DOI)
    Note
    Original publication: Jan T Lundgren and Anders Peterson, A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem, 2008, Transportation Research Part B: Methodological, (42), 4, 339-354. http://dx.doi.org/10.1016/j.trb.2007.09.005. Copyright: Elsevier B.V., http://www.elsevier.com/Available from: 2008-04-03 Created: 2008-04-03 Last updated: 2018-08-23
    3. Methods for Pre-Adjusting Time-Dependent Origin–Destination Matrices: an Application to Gothenburg
    Open this publication in new window or tab >>Methods for Pre-Adjusting Time-Dependent Origin–Destination Matrices: an Application to Gothenburg
    2003 (English)In: Proceedings of the 10th World Congress and Exhibition on Intelligent Transport Systems and Services, Madrid, Spain, November 16–20, 2003, no 2436Conference paper, Published paper (Refereed)
    Abstract [en]

    We present a number of schemes for adjusting time-dependent travel demand information with respect to link flow observations. The aim is to utilize the structure of the given OD-matrix, which is compounded from different sources, for making simple overall adjustments. These pre-adjustments are then followed up with a complete OD-estimation procedure, such as that in Contram. Numerical results from the city of Gothenburg are presented.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-14467 (URN)
    Conference
    10th World Congress and Exhibition on Intelligent Transport Systems and Services, Madrid, Spain, November 16–20
    Available from: 2007-06-04 Created: 2007-06-04 Last updated: 2018-08-23
  • 40. Order onlineBuy this publication >>
    Peterson, Anders
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    The Origin-Destination Matrix Estimation Problem: Analysis and Computations2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    For most kind of analyses in the field of traffic planning, there is a need for origin--destination (OD) matrices, which specify the travel demands between the origin and destination nodes in the network. This thesis concerns the OD-matrix estimation problem, that is, the calculation of OD-matrices using observed link flows. Both time-independent and time-dependent models are considered, and we also study the placement of link flow detectors.

    Many methods have been suggested for OD-matrix estimation in time-independent models, which describe an average traffic situation. We assume a user equilibrium to hold for the link flows in the network and recognize a bilevel structure of the estimation problem. A descent heuristic is proposed, in which special attention is given to the issue of calculating the change of a link flow with respect to a change of the travel demand in a certain pair of origin and destination nodes.

    When a time-dimension is considered, the estimation problem becomes more complex. Besides the problem of distributing the travel demand onto routes, the flow propagation in time and space must also be handled. The time-dependent OD-matrix estimation problem is the subject for two studies. The first is a case study, where the conventional estimation technique is improved through introducing pre-adjustment schemes, which exploit the structure of the information contained in the OD-matrix and the link flow observations. In the second study, an algorithm for time-independent estimation is extended to the time-dependent case and tested for a network from Stockholm, Sweden.

    Finally, we study the underlying problem of finding those links where traffic flow observations are to be performed, in order to ensure the best possible quality of the estimated OD-matrix. There are different ways of quantifying a common goal to cover as much traffic as possible, and we create an experimental framework in which they can be evaluated. Presupposing that consistent flow observations from all the links in the network yields the best estimate of the OD-matrix, the lack of observations from some links results in a relaxation of the estimation problem, and a poorer estimate. We formulate the problem to place link flow detectors as to achieve the least relaxation with a limited number of detectors.

    List of papers
    1. A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem
    Open this publication in new window or tab >>A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem
    2008 (English)In: Transportation Research Part B: Methodological, ISSN 0191-2615, E-ISSN 1879-2367, Vol. 42, no 4, p. 339-354Article in journal (Refereed) Published
    Abstract [en]

    In this paper we consider the estimation of an origin–destination (OD) matrix, given a target OD-matrix and traffic counts on a subset of the links in the network. We use a general nonlinear bilevel minimization formulation of the problem, where the lower level problem is to assign a given OD-matrix onto the network according to the user equilibrium principle. After reformulating the problem to a single level problem, the objective function includes implicitly given link flow variables, corresponding to the given OD-matrix. We propose a descent heuristic to solve the problem, which is an adaptation of the wellknown projected gradient method. In order to compute a search direction we have to approximate the Jacobian matrix representing the derivatives of the link flows with respect to a change in the OD-flows, and we propose to do this by solving a set of quadratic programs with linear constraints only. If the objective function is differentiable at the current point, the Jacobian is exact and we obtain a gradient. Numerical experiments are presented which indicate that the solution approach can be applied in practice to medium to large size networks.

    Place, publisher, year, edition, pages
    Institutionen för teknik och naturvetenskap, 2008
    Keywords
    Origin-Destination matrix; Sensitivity analysis; User-equilibrium
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-11461 (URN)10.1016/j.trb.2007.09.005 (DOI)
    Note
    Original publication: Jan T Lundgren and Anders Peterson, A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem, 2008, Transportation Research Part B: Methodological, (42), 4, 339-354. http://dx.doi.org/10.1016/j.trb.2007.09.005. Copyright: Elsevier B.V., http://www.elsevier.com/Available from: 2008-04-03 Created: 2008-04-03 Last updated: 2018-08-23
    2. Methods for Pre-Adjusting Time-Dependent Origin–Destination Matrices: an Application to Gothenburg
    Open this publication in new window or tab >>Methods for Pre-Adjusting Time-Dependent Origin–Destination Matrices: an Application to Gothenburg
    2003 (English)In: Proceedings of the 10th World Congress and Exhibition on Intelligent Transport Systems and Services, Madrid, Spain, November 16–20, 2003, no 2436Conference paper, Published paper (Refereed)
    Abstract [en]

    We present a number of schemes for adjusting time-dependent travel demand information with respect to link flow observations. The aim is to utilize the structure of the given OD-matrix, which is compounded from different sources, for making simple overall adjustments. These pre-adjustments are then followed up with a complete OD-estimation procedure, such as that in Contram. Numerical results from the city of Gothenburg are presented.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-14467 (URN)
    Conference
    10th World Congress and Exhibition on Intelligent Transport Systems and Services, Madrid, Spain, November 16–20
    Available from: 2007-06-04 Created: 2007-06-04 Last updated: 2018-08-23
    3. A Heuristic for the Estimation of Time-Dependent Origin Origin–Destination Matrices from Traffic Counts
    Open this publication in new window or tab >>A Heuristic for the Estimation of Time-Dependent Origin Origin–Destination Matrices from Traffic Counts
    2007 (English)In: Nordic MPS ’04, Norrköping, Sweden, October 21–23, 2004 and The 10th Jubilee Meeting of the EURO Working Group on Transportation, Poznan, Poland, September 13–16, 2005 and Transportforum, Linköping, Sweden, January 11–12, 2006, 2007Conference paper, Published paper (Refereed)
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-14468 (URN)
    Conference
    The 10th Jubilee Meeting of the EURO Working Group on Transportation, Poznan, Poland, September 13–16, 2005
    Available from: 2007-06-04 Created: 2007-06-04 Last updated: 2018-08-23
    4. Allocation of Link Flow Detectors for Origin-Destination Matrix Estimation-A Comparative Study
    Open this publication in new window or tab >>Allocation of Link Flow Detectors for Origin-Destination Matrix Estimation-A Comparative Study
    2010 (English)In: COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, ISSN 1093-9687, Vol. 25, no 2, p. 116-131Article in journal (Refereed) Published
    Abstract [en]

    Origin-destination (OD) matrices are essential for various analyses in the field of traffic planning, and they are often estimated from link flow observations. We compare methods for allocating link flow detectors to a traffic network with respect to the quality of the estimated OD-matrix. First, an overview of allocation methods proposed in the literature is presented. Second, we construct a controlled experimental environment where any allocation method can be evaluated, and compared to others, in terms of the quality of the estimated OD-matrix. Third, this environment is used to evaluate and compare three fundamental allocation methods. Studies are made on the Sioux Falls network and on a network modeling the city of Linkoping. Our conclusion is, that the most commonly studied approach for detector allocation, maximizing the coverage of OD-pairs, seems to be unfavorable for the quality of the estimated OD-matrix.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-53695 (URN)10.1111/j.1467-8667.2009.00625.x (DOI)
    Available from: 2010-02-01 Created: 2010-02-01 Last updated: 2018-08-23
    5. A Novel Model for Placement of Detectors for Origin–Destination Matrix Estimation
    Open this publication in new window or tab >>A Novel Model for Placement of Detectors for Origin–Destination Matrix Estimation
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-14470 (URN)
    Available from: 2007-06-04 Created: 2007-06-04 Last updated: 2010-01-13
    Download full text (pdf)
    FULLTEXT01
  • 41.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Towards a robust traffic timetable for the Swedish Southern Mainline2012In: Computers in Railways XIII: Computer System Design and Operation in the Railway and Other Transit Systems / [ed] C.A. Brebbia, N. Tomil, J.M. Mera, B. Ning & P. Tzieropoulos, Ashurst: WIT Press, 2012, p. 473-484Conference paper (Other academic)
    Abstract [en]

    We identify the on-time performance as a key to evaluate a railway timetable’s robustness to disturbances and evaluate the on-time performance for two single services on the Swedish Southern Mainline for the autumn period 2011. We analyse the punctuality by studying how the performance develops en route. Typically the time spent in the stations is underestimated, which partly is compensated for by time margins along the line, giving rise to a sawtooth formed delay muster with an increasing trend. The standard deviation in the delay reports seems to be a good indicator for the precision in the traffic. In this material it is almost linearly increasing with a good minute per hour scheduled running time. Two attempts are made to change the timetable for a better performance. By using socio-economic values a customer-oriented description of the current timetable is calculated as a trade-off between high punctuality and short travel time. This timetable does not affect any other traffic. Minor effects to other traffic would be the result if the existing margins are re-distributed to better match the demand en route in some sense. As long as no more time supplement is added, we will, however, not improve on the punctuality to the final destination. For future research is left, how the decrease in precision can be accounted for already in the timetable construction.

    Download full text (pdf)
    fulltext
  • 42.
    Peterson, Anders
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Traffic Demand Modeling and Origin-Destination Matrix EstimationManuscript (preprint) (Other academic)
    Abstract [en]

    An origin-destination (OD) matrix describes the travel demand between all pairs of origins and destinations in a traffic network. OD-matrices are essential input for most types traffic models, both for long-term planning, where the actions are meant to be permanent, and for short-term planning, where the operational situation is managed. This paper is a literature overview of models and methods for obtaining reliable OD-matrices.

    We present the Four-stage model which is commonly used for sequentially computing the number of trips starting and terminating at the centroid nodes, the distribution to travel demand between origins and destinations, the split onto different travel modes and the choice-based assignment of routes and links in the network. Further, we identify the information contained in traffic counts as an important source for adjusting the computed OD-matrix. The generic OD-matrix estimation problem from link flow observations is formulated and we discuss different solution techniques and how they relate to the assumptions used for the assignment of travel demand to routes and links.

    Time-dependence is a fundamental difference between the model types. A time-independent (static) model describes a steady state, which represents and average situation. If the interaction between sequential time periods is to be analyzed, however, a dynamic model is required. The time dimension is a complicating factor, since not only the route choice, but also the flow propagation must be taken care of in the model. Especially those models where the OD-matrix is to be estimated in real-time, must be simplified as to the computational effort.

  • 43.
    Peterson, Anders
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Bohlin, Markus
    KTH Royal Inst Technol, Sweden; Malardalen Univ, Sweden.
    Joborn, Martin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. RISE Res Inst Sweden, Sweden.
    Guest editorial for the best papers of RailNorrkoping 20192020In: Journal of Rail Transport Planning & Management, ISSN 2210-9706, E-ISSN 2210-9714, Vol. 15, article id 100204Article in journal (Other academic)
    Abstract [en]

    n/a

  • 44.
    Peterson, Anders
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Polishchuk, Valentin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Applying Geometric Thick Paths to Compute the Maximum Number of Additional Train Paths in a Railway Timetable2019Conference paper (Refereed)
  • 45.
    Peterson, Anders
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Wahlborg, Magnus
    Railway Traffic and sale, Trafikverket, Borlänge.
    Häll, Carl Henrik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Kordnejad, Behzad
    Transportplanering, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Warg, Jennifer
    Transportplanering, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Johansson, Ingrid
    Transportplanering, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Joborn, Martin
    Systems Engineering, RISE Research Institutes of Sweden, Göteborg, Sweden.
    Gestrelius, Sara
    Systems Engineering, RISE Research Institutes of Sweden, Göteborg, Sweden.
    Törnquist Krasemann, Johanna
    Department of Computer Science, Blekinge tekniska högskola, Karlskrona, Sweden.
    Josyula, Sai Prashanth
    Department of Computer Science, Blekinge tekniska högskola, Karlskrona, Sweden.
    Palmqvist, Carl-William
    Transport Systems and Logistics, Lund University, Sweden.
    Lidén, Tomas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Deliverable D 3.1: Analysis of the gap between daily timetable and operational traffic2019Report (Other academic)
    Abstract [en]

    Fr8Rail II/Work-Package 3 Real-time network management and improved methods for timetable planning addresses the problem to improve capacity and punctuality in the railway system by developing concepts and methods for tactical planning and operational traffic. In this report the state-of-the-art has been summarised.

    The aim of the project is to:

    • Propose concepts and methods that improve the annual and short-term timetable planning.
    • Demonstrate how the proposed timetable planning concepts improve the prerequisites for real-time network management.
    • Develop methods and tools that can reduce inefficiencies in real time network management.

    An important aspect is to improve the coordination between yards/terminals and the line network, and between Infrastructure Manager, Yard Managers, and freight Rail Undertakings.

    We motivate our research by the current situation in Sweden, which is characterised by low on-time performance for freight trains, dense and heterogenous traffic on the major railway lines, and a rigid annual timetabling process, which is non-suitable for short-term changes. We believe that better tools for network planning and management on tactical and operational level can help to connect planning and operational processes.

    Aiming for improvements of the operational traffic, there is a need for systematic development of methods applied at several planning horizons, based on both simulation and optimization techniques. Close to operation fast methods are needed, for example, based on meta-heuristics.

    The maintenance planning process and improvement potential have been described. This is a new piece of the puzzle and it is important to close the gap between timetable planning and operational traffic. The different planning processes at the Infrastructure Manager, the Rail Undertakings and the Maintenance Contractors should be aligned.

    When developing new approaches for computational decision-support tools for real-time network management, it is important — but very challenging — to evaluate and benchmark with existing software tools. We also observe that the research stream on computational decision-support and algorithm development for railway traffic management has not yet been sufficiently merged with the corresponding research stream focusing on aspects of human computer interaction.

    Download full text (pdf)
    fulltext
  • 46.
    Solinen, Emma
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Trafikverket, Sundbyberg, Sweden.
    Nicholson, Gemma
    Birmingham Centre for Railway Research and Education, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    A microscopic evaluation of railway timetable robustness and critical points2017In: Journal of Rail Transport Planning & Management, ISSN 2210-9706, E-ISSN 2210-9714, Vol. 7, no 4, p. 207-223Article in journal (Refereed)
    Abstract [en]

    One method to increase the quality of railway traffic flow is to construct a more robust timetable in which trains are able both to recover from delays and the delays are prevented from propagating. Previous research results show that the indicator Robustness in Critical Points (RCP) can be used to increase timetable robustness. In this paper we present the use of a method for RCP optimization: how it can be assessed ex-post via microscopic simulation. From the evaluation we learn more about how increased RCP values influence a timetable's performance. The aim is to understand more about RCP increase at a localised level within a timetable in terms of effects to the pairs of trains that are part of the indicator. We present a case study where an initial timetable and a timetable with increased RCP values are evaluated. The ex-post evaluation includes the quantification of measures concerning train-borne delay and robustness of operations, as well as measures capturing the subsequent quality of service experienced by passengers to assess the broader effects of improved robustness. The result shows that it is necessary to use several key performance indicators (KPIs) to evaluate the effects of an RCP increase. The robustness increases at a localised level, but the results also indicate that there is a need to analyse the relationship between ex-post measures and RCP further, to improve the method used to increase RCP and thus its overall effect on timetable robustness.

  • 47.
    Solinen, Emma
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Trafikverket, Sundbyberg, Sweden.
    Nicholson, Gemma
    Birmingham Centre for Railway Research and Education, University of Birmingham, Unnited Kingdom.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    A Microscopic Evaluation of Robustness in Critical Points2017In: 7th International Conference on RailwayOperations Modelling and Analysis (RailLille 2017) / [ed] N. Tomii, I.A. Hansen, J. Rodriguez, P. Pellegrini, S. Dauzère-Pérès, D. De Almeida, International Association of Railway Operations Research , 2017, p. 83-103, article id 1705Conference paper (Refereed)
    Abstract [en]

    One method to increase the quality of railway traffic flow is to construct a more robust timetable in which trains are able to both recover from delays and the delays are prevented from propagating. Previous research results show that the indicator Robustness in Critical Points (RCP) can be used to increase timetable robustness. In this paper we present the use of a method for RCP optimization, how can be implemented and assessed ex-post via microscopic simulation and subsequently evaluated. From the evaluation we learn more about how increased RCP values influence a timetable’s performance. The aim is to understand more about RCP increase at a localised level within a timetable in terms of effects to the pairs of trains that are part of the indicator. We present a case study where an initial timetable and a timetable with increased RCP values are evaluated. The ex-post evaluation includes the quantification of measures concerning train-borne delay and robustness of traffic flow, as well as measures capturing the subsequent quality of service experienced by passengers to assess the broader effects of improved robustness. The result shows that it is necessary to use several Key Performance Indicators (KPIs) to evaluate the effects of an RCP increase. The robustness will increase at a localised level, but the results also indicate that there is a need to analyse the relationship between ex-post measures and RCP further, to improve the method used to increase RCP and thus its overall effect on timetable robustness.

    Download full text (pdf)
    A Microscopic Evaluation of Robustness in Critical Points
  • 48.
    Wahlborg, Magnus
    et al.
    Swedish Transport Administration (Trafikverket), Borlänge, Sweden.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Gruosso, Lucia
    Ansaldo STS, Genova, Italy.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Jalili, Leila
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    D3.1 – Final pre-study for an improved methodology for timetable planning including state-of-the-art and future work plan2018Report (Other academic)
    Abstract [en]

    In ARCC project work package 3, research and innovation activities have been done to identify areas with a need for improved timetable planning methods and outline how new methods can be developed and implemented.

    Improved timetable planning scope were described and there was an activity to connect to other relevant Shift2Rail projects. An workshop was organised in Stockholm 2018-05-29.

    State of the art in practice was described for timetable planning in Sweden, UIC 406 method and Ansaldo STS Traffic management systems. Also state of the art in algorithms was described.

    Future work plan research needs areas are:

    1. Understanding of various goals for timetabling and how they co-variate

    2. Residual capacity

    3. Connection and coordination of the planning processes

    4. Connection and coordination of the yard/terminal planning and network planning

    5. Integration of freight trains into the timetable, focusing on short-term and ad-hoc

    6. Integration of maintenance scheduling and timetabling, at all planning stages

    7. Improved decision support for handeling of deviations from timetable in operations

    8. Features of planning tools, and implementation of automatized timetabling

    Download full text (pdf)
    fulltext
  • 49.
    Yu, Liyun
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Häll, Carl Henrik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    A MILP Model for Rescheduling Freight Trains under an Unexpected Marshalling-Yard Closure2023In: Book of Abstracts / [ed] Rob Goverde, Francesco Corman, Ivan Belošević, Sanjin Milinković, The Faculty of Transport and Traffic Engineering, University of Belgrade, Serbia , 2023, p. 68-68Conference paper (Other academic)
    Abstract [en]

    This study is about rescheduling freight trains to reduce the eff ects of major interruptions. In this paper, we consider that the interruption is an unexpected marshallingyard closure. We develop a macroscopic Mixed-Integer Linear Programming (MILP)model to reschedule railway timetables. One important principle is that we simultaneously reschedule several trains, instead of one-by-one. Furthermore, we consider arescheduling strategy of letting trains wait on the way when the destination yard havea closure. The model considers stopping restrictions and the capacity of each segmentand station. The order of the trains aff ected by the interruption is not fi xed. We presentexperimental results of three diff erent cases, which are all based on artifi cial data.

  • 50.
    Yu, Liyun
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Häll, Carl Henrik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Peterson, Anders
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Schmidt, Christiane
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    A MILP model for rescheduling freight trains under an unexpected marshalling-yard closure2023Conference paper (Other academic)
    Abstract [en]

    This study is about rescheduling freight trains to reduce the effects of major interruptions. In this paper, we consider that the interruption is an unexpected marshalling-yard closure. We develop a macroscopic Mixed-Integer Linear Programming (MILP) model to reschedule railway timetables. One important principle is that we simultaneously reschedule several trains, instead of one-by-one. Furthermore, we consider a rescheduling strategy of letting trains wait on the way when the destination yard have a closure. The model considers stopping restrictions and the capacity of each segment and station. The order of the trains affected by the interruption is not fixed. We present experimental results of three different cases, which are all based on artificial data.

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