Freight Transport by Rail
01 Jan 2015-pp 391-411
TL;DR: This chapter discusses the train design problem, and develops an algorithm for it based on the minimum cost spanning tree approach, and the solution of the RAS 2011 contest problem using it.
Abstract: The train design problem (also called "block-to-train assignment problem") is a difficult combinatorial optimization problem encountered daily in the freight railroad industry. In 2011, the Railway Applications Society (RAS) of the professional society INFORMS had set up a competition problem of this based on a simplified real-life instance, which is the basis for this chapter. In this chapter we discuss this problem, and develop an algorithm for it based on the minimum cost spanning tree approach, and the solution of the RAS 2011 contest problem using it.
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TL;DR: A graph theoretic formulation for the train timetabling problem using a directed multigraph in which nodes correspond to departures/arrivals at a certain station at a given time instant is proposed, used to derive an integer linear programming model that is relaxed in a Lagrangian way.
Abstract: The train timetabling problem aims at determining a periodic timetable for a set of trains that does not violate track capacities and satisfies some operational constraints. In particular, we concentrate on the problem of a single, one-way track linking two major stations, with a number of intermediate stations in between. Each train connects two given stations along the track (possibly different from the two major stations) and may have to stop for a minimum time in some of the intermediate stations. Trains can overtake each other only in correspondence of an intermediate station, and a minimum time interval between two consecutive departures and arrivals of trains in each station is specified.In this paper, we propose a graph theoretic formulation for the problem using a directed multigraph in which nodes correspond to departures/arrivals at a certain station at a given time instant. This formulation is used to derive an integer linear programming model that is relaxed in a Lagrangian way. A novel feature of our model is that the variables in the relaxed constraints are associated only with nodes (as opposed to arcs) of the aforementioned graph. This allows a considerable speed-up in the solution of the relaxation. The relaxation is embedded within a heuristic algorithm which makes extensive use of the dual information associated with the Lagrangian multipliers. We report extensive computational results on real-world instances provided from Ferrovie dello Stato SpA, the Italian railway company, and from Ansaldo Segnalamento Ferroviario SpA.
459 citations
"Freight Transport by Rail" refers background in this paper
...The complexity of the train design problem has been well-acknowledged in both practice and academia, see [1–5, 7, 10]....
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...Interested readers may refer to a few references given at the end of this chapter among [1–8, 10]....
[...]
TL;DR: In this paper, the authors report on the existing literature models for rail transportation with two goals in mind: (a) to collect and categorize rail modelling efforts, and (b) to position the rail-related literature in the context of other transportation models and provide an introduction to this field for nonspecialists.
307 citations
"Freight Transport by Rail" refers background in this paper
...The complexity of the train design problem has been well-acknowledged in both practice and academia, see [1–5, 7, 10]....
[...]
...Interested readers may refer to a few references given at the end of this chapter among [1–8, 10]....
[...]
TL;DR: A general modeling framework, based on a network optimization model, is presented, which may be used to assist and enhance the tactical and strategic planning process for such a system.
Abstract: We examine the freight transportation problem which occurs when the same authority controls and plans both the supply of transportation services (modes, routes, frequencies for the services and classification, consolidation, transfer policies for terminals) and the routing of freight. We present a general modeling framework, based on a network optimization model, which may be used to assist and enhance the tactical and strategic planning process for such a system. The problem is solved by means of an algorithm, described in some detail, based on decomposition and column generation principles. We also present detailed results on the behaviour and performance of the algorithm, as observed during experimentation with a specific rail application.
235 citations
"Freight Transport by Rail" refers background in this paper
...The complexity of the train design problem has been well-acknowledged in both practice and academia, see [1–5, 7, 10]....
[...]
...Interested readers may refer to a few references given at the end of this chapter among [1–8, 10]....
[...]
TL;DR: In this article, a local feedback-based travel advance strategy is developed using a discrete event model of train advances along lines of the railway, which is shown to perform well on three time-performance criteria while maintaining the local nature of the strategy.
Abstract: Scheduling trains in a railway network is a fundamental operational problem in the railway industry. A local feedback-based travel advance strategy is developed using a discrete event model of train advances along lines of the railway. This approach can quickly handle perturbations in the schedule and is shown to perform well on three time-performance criteria while maintaining the local nature of the strategy. If the local strategy leads to a deadlock, a capacity check algorithm is applied that prevents deadlock, but requires additional nonlocal information. Extensions to the strategy are developed for networks with double-track sections and with variable train characteristics and priorities.
231 citations
"Freight Transport by Rail" refers background in this paper
...The complexity of the train design problem has been well-acknowledged in both practice and academia, see [1–5, 7, 10]....
[...]
...Interested readers may refer to a few references given at the end of this chapter among [1–8, 10]....
[...]
Book•
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TL;DR: This work describes a tool, FlowChecker, to identify any intra-switch misconfiguration within a single FlowTable and describes the inter-switch or inter-federated inconsistencies in a path of OpenFlow switches across the same or different OpenFlow infrastructures.
Abstract: It is difficult to build a real network to test novel experiments. OpenFlow makes it easier for researchers to run their own experiments by providing a virtual slice and configuration on real networks. Multiple users can share the same network by assigning a different slice for each one. Users are given the responsibility to maintain and use their own slice by writing rules in a FlowTable. Misconfiguration problems can arise when a user writes conflicting rules for single FlowTable or even within a path of multiple OpenFlow switches that need multiple FlowTables to be maintained at the same time. In this work, we describe a tool, FlowChecker, to identify any intra-switch misconfiguration within a single FlowTable. We also describe the inter-switch or inter-federated inconsistencies in a path of OpenFlow switches across the same or different OpenFlow infrastructures. FlowChecker encodes FlowTables configuration using Binary Decision Diagrams and then uses the model checker technique to model the inter-connected network of OpenFlow switches.
212 citations