58,842 research outputs found

    Train Timetable Design for Shared Railway Systems using a Linear Programming Approach to Approximate Dynamic Programming

    Get PDF
    In the last 15 years, the use of rail infrastructure by different train operating companies (shared railway system) has been proposed as a way to improve infrastructure utilization and to increase efficiency in the railway industry. Shared use requires coordination between the infrastructure manager and multiple train operators in a competitive framework, so that regulators must design appropriate capacity pricing and allocation mechanisms. However, the resulting capacity utilization from a given mechanism in the railway industry cannot be known in the absence of operations. Therefore assessment of capacity requires the determination of the train timetable, which eliminates any potential conflicts in bids from the operators. Although there is a broad literature that proposes train timetabling methods for railway systems with single operators, there are few models for shared competitive railway systems. This paper proposes a train timetabling model for shared railway systems that explicitly considers network effects and the existence of multiple operators requesting to operate several types of trains traveling along different routes in the network. The model is formulated and solved both as a mixed integer linear programming (MILP) problem (using a commercial solver) and as a dynamic programming (DP) problem. We solve the DP formulation with a novel algorithm based on a linear programming (LP) approach to approximate dynamic programming (ADP) that can solve much larger problems than are computationally intractable with commercial MILP solvers. The model simulates the optimal decisions by an infrastructure manager for a shared railway system with respect to a given objective function and safety constraints. This model can be used to evaluate alternative capacity pricing and allocation mechanism. We demonstrate the method for one possible capacity pricing and allocation mechanism, and show how the competing demands and the decisions of the infrastructure manager under this mechanism impact the operations on a shared railway system for all stakeholders

    GRASP algorithms for the robust railway network design problem

    Full text link
    This paper analyzes the solvability of a railway network design problem and its robust version. These problems are modeled as integer linear programming problems with binary variables, and their solutions provide topological railway networks maximizing the trip coverage in the presence of a competing mode, both assuming that the network works fine and that links can fail, respectively. Since these problems are computationally intractable for realistic sizes, GRASP heuristics are proposed for finding good feasible solutions. The results obtained in a computational experience indicate that our GRASP algorithms are suitable for railway network design problems. © 2011 Springer Science+Business Media, LLC.We would like to thank the Spanish Ministerio de Fomento under grant PT-2007-003, Ministerio de Ciencia y Educacion under grant MTM2009-14243, the Junta de Andalucia under grant P09-TEP-5022 for supporting this research, the FEDER funds of the European Union and TUSSAM (Seville, Spain). Special thanks are due to two anonymous referees for their valuable comments.García-Archilla, B.; Lozano, AJ.; Mesa, JA.; Perea Rojas Marcos, F. (2011). GRASP algorithms for the robust railway network design problem. Journal of Heuristics. 19(2):399-422. https://doi.org/10.1007/s10732-011-9185-zS399422192Baaj, M., Mahmassani, H.: An AI-based approach for transit route system planning and design. J. Adv. Transp. 25(2), 187–210 (1991)Cancela, H., Robledo, F., Rubino, G.: A grasp algorithm with tree based local search for designing a survivable wide area network backbone. J. Comput. Sci. Technol. 4(1), 52–58 (2004)Díaz, J.A., Luna, D., Luna, R.: A grasp heuristic for the manufacturing cell formation problem. TOP (2011). doi: 10.1007/s11750-010-0159-3Feo, T., Resende, M.: A probabilistic heuristic for a computationally difficult set covering problem. Oper. Res. Lett. 8, 67–71 (1989)Goossens, J., van Hoesel, C., Kroon, L.: A branch-and-cut approach for solving railway line-planning problems. Transp. Sci. 38, 379–393 (2004)Institute of Electrical and Electronics Engineers: IEEE Standard Computer Dictionary: A Compilation of IEEE Standard Computer Glossaries (1990)Laporte, G., Mesa, J., Perea, F.: A game theoretic framework for the robust railway transit network design problem. Transp. Res., Part B, Methodol. 44, 447–459 (2010)Laporte, G., Marín, A., Mesa, J., Perea, F.: Designing robust rapid transit networks with alternative routes. J. Adv. Transp. 45, 54–65 (2011)Marín, A., García-Ródenas, R.: Location of infrastructure in urban railway networks. Comput. Oper. Res. 36, 1461–1477 (2009)Marín, A., Jaramillo, P.: Urban rapid transit network design: accelerated Benders decomposition. Ann. Oper. Res. 169(1), 35–53 (2009)Marín, A., Mesa, J.A., Perea, F.: Integrating robust railway network design and line planning under failures. Lect. Notes Comput. Sci. 5868, 273–292 (2009)Mauttone, A., Urquhart, M.E.: A route set construction algorithm for the transit network design problem. Comput. Oper. Res. 36, 2440–2449 (2009)Murphey, R., Pardalos, P., Pitsoulis, L.: A GRASP for the multitarget multisensor tracking problem. In: Networks. Discrete Mathematics and Theoretical Computer Science Series, vol. 40, pp. 277–302. American Mathematical Society, Providence (1998)Nesmachnow, S., Cancela, H., Alba, E.: Evolutionary algorithms applied to reliable communication network design. Eng. Optim. 39(7), 831–855 (2007)Schöbel, A., Scholl, S.: Line planning with minimal transfers. In: 5th Workshop on Algorithmic Methods and Models for Optimization of Railways, Number 06901 in Dagstuhl Seminar Proceedings (2006

    Robust Train Routing and Online Re-scheduling

    Get PDF
    Train Routing is a problem that arises in the early phase of the passenger railway planning process, usually several months before operating the trains. The main goal is to assign each train a stopping platform and the corresponding arrival/departure paths through a railway station. It is also called Train Platforming when referring to the platform assignment task. Railway stations often represent bottlenecks and train delays can easily disrupt the routing schedule. Thereby railway stations are responsible for a large part of the delay propagation in the whole network. In this research we present different models to compute robust routing schedules and we study their power in an online context together with different re-scheduling strategies. We also design a simulation framework and use it to evaluate and compare the effectiveness of the proposed robust models and re-scheduling algorithms using real-world data from Rete Ferroviaria Italiana, the main Italian Railway Infrastructure Manager

    An integer programming model for analysing impacts of different train types on railway line capacity

    Get PDF
    The evaluation of railway line capacity is an important problem, which effects majority of problems in rail transportation planning. The railway capacity is dependent on infrastructure, traffic, and operating parameters. A key factor affecting railway line capacity is the impact of different train types. As the combination of different train types increases, more interference is generated. In this paper, for evaluation of train type interactions on railway line capacity, an integer-programming model for both line and line section is presented. The problem is formulated as a multicommodity network design model on a space-discrete time network. The railway capacity is calculated using data typically available to planners. The inputs of the model are the characteristic of each train type and railway line attributes. The model determines railway capacity based on train type mixes. In addition, this model considers impact of train types on capacity and waiting time. In order to show the features of the model, a case study is implemented in Iran Railways. The capacity tends to increase non-linearly with small incremental changes in parameters. The mixture of train types reduces the railway line capacity. The proposed model can help railway managers for long-term planning

    A game theoretic model for re-optimizing a railway timetable

    Get PDF
    The Setting In the Nineties of the last century the European Commission decided to open the railway market to competition, allowing different railway companies to operate on the same network. Under this framework Infrastructure Managers have to allocate capacity in order to define the timetable, dealing with possible slot conflicts between competing Transport Operators. The Problem An efficient train scheduling requires collecting a lot of information from the Transport Operators, but it may not be in their interests to reveal their private information. Therefore, it may be useful for real-world applications to design methods that provide incentives to Transport Operators for cooperating with the aim of increasing their utility; moreover, this may result in an improvement of the efficiency even for the Infrastructure Managers, so they also have incentives for favouring the cooperation. The Proposal In this paper we propose a game theoretical model in which the agents (Transport Operators) exchange information on their needs and are compensated by a possible increasing of their utility. This approach represents the situation as a coalition formation problem. In particular, we refer to the C-Solution proposed by Gerber (Rev Econ Design 5:149–175, 1), which is applied to some examples, each with different features. This model requires that information is revealed to a small number of competitors. This is rather important in a market currently still characterized by operator reluctance to an indiscriminate diffusion of information. Furthermore, the low dimension of the problem allows having a low computational complexity

    An intelligent framework and prototype for autonomous maintenance planning in the rail industry

    Get PDF
    This paper details the development of the AUTONOM project, a project that aims to provide an enterprise system tailored to the planning needs of the rail industry. AUTONOM extends research in novel sensing, scheduling, and decision-making strategies customised for the automated planning of maintenance activities within the rail industry. This paper sets out a framework and software prototype and details the current progress of the project. In the continuation of the AUTONOM project it is anticipated that the combination of techniques brought together in this work will be capable of addressing a wider range of problem types, offered by Network rail and organisations in different industries

    A review of key planning and scheduling in the rail industry in Europe and UK

    Get PDF
    Planning and scheduling activities within the rail industry have benefited from developments in computer-based simulation and modelling techniques over the last 25 years. Increasingly, the use of computational intelligence in such tasks is featuring more heavily in research publications. This paper examines a number of common rail-based planning and scheduling activities and how they benefit from five broad technology approaches. Summary tables of papers are provided relating to rail planning and scheduling activities and to the use of expert and decision systems in the rail industry.EPSR

    Promoting Intermodal Connectivity at California’s High Speed Rail Stations

    Get PDF
    High-speed rail (HSR) has emerged as one of the most revolutionary and transformative transportation technologies, having a profound impact on urban-regional accessibility and inter-city travel across Europe, Japan, and more recently China and other Asian countries. One of HSR’s biggest advantages over air travel is that it offers passengers a one-seat ride into the center of major cities, eliminating time-consuming airport transfers and wait times, and providing ample opportunities for intermodal transfers at these locales. Thus, HSR passengers are typically able to arrive at stations that are only a short walk away from central business districts and major tourist attractions, without experiencing any of the stress that car drivers often experience in negotiating such highly congested environments. Such an approach requires a high level of coordination and planning of the infrastructural and spatial aspects of the HSR service, and a high degree of intermodal connectivity. But what key elements can help the US high-speed rail system blend successfully with other existing rail and transit services? That question is critically important now that high-speed rail is under construction in California. The study seeks to understand the requirements for high levels of connectivity and spatial and operational integration of HSR stations and offer recommendations for seamless, and convenient integrated service in California intercity rail/HSR stations. The study draws data from a review of the literature on the connectivity, intermodality, and spatial and operational integration of transit systems; a survey of 26 high-speed rail experts from six different European countries; and an in-depth look of the German and Spanish HSR systems and some of their stations, which are deemed as exemplary models of station connectivity. The study offers recommendations on how to enhance both the spatial and the operational connectivity of high-speed rail systems giving emphasis on four spatial zones: the station, the station neighborhood, the municipality at large, and the region

    Multi-objective model for optimizing railway infrastructure asset renewal

    Get PDF
    Trabalho inspirado num problema real da empresa Infraestruturas de Portugal, EP.A multi-objective model for managing railway infrastructure asset renewal is presented. The model aims to optimize three objectives, while respecting operational constraints: levelling investment throughout multiple years, minimizing total cost and minimizing work start postponements. Its output is an optimized intervention schedule. The model is based on a case study from a Portuguese infrastructure management company, which specified the objectives and constraints, and reflects management practice on railway infrastructure. The results show that investment levelling greatly influences the other objectives and that total cost fluctuations may range from insignificant to important, depending on the condition of the infrastructure. The results structure is argued to be general and suggests a practical methodology for analysing trade-offs and selecting a solution for implementation.info:eu-repo/semantics/publishedVersio
    • …
    corecore