1,352 research outputs found

    Computer-based decision support for railway traffic scheduling and dispatching: A review of models and algorithms

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    This paper provides an overview of the research in railway scheduling and dispatching. A distinction is made between tactical scheduling, operational scheduling and re-scheduling. Tactical scheduling refers to master scheduling, whereas operational scheduling concerns scheduling at a later stage. Re-scheduling focuses on the re-planning of an existing timetable when deviations from it have occurred. 48 approaches published between 1973 and 2005 have been reviewed according to a framework that classifies them with respect to problem type, solution mechanism, and type of evaluation. 26 of the approaches support the representation of a railway network rather than a railway line, but the majority has been experimentally evaluated for traffic on a line. 94 % of the approaches have been subject to some kind of experimental evaluation, while approximately 4 % have been implemented. The solutions proposed vary from myopic, priority-based algorithms, to traditional operations research techniques and the application of agent technology.This paper provides an overview of the research in railway scheduling and dispatching. A distinction is made between tactical scheduling, operational scheduling and re-scheduling. Tactical scheduling refers to master scheduling, whereas operational scheduling concerns scheduling at a later stage. Re-scheduling focuses on the re-planning of an existing timetable when deviations from it have occurred. 48 approaches published between 1973 and 2005 have been reviewed according to a framework that classifies them with respect to problem type, solution mechanism, and type of evaluation. 26 of the approaches support the representation of a railway network rather than a railway line, but the majority has been experimentally evaluated for traffic on a line. 94 % of the approaches have been subject to some kind of experimental evaluation, while approximately 4 % have been implemented. The solutions proposed vary from myopic, priority-based algorithms, to traditional operations research techniques and the application of agent technology

    Regulating privatized rail transport

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    Traditionally, transport regulation has been viewed as an exercise in second-best optimization, acknowledging the existence of huge information problems. Then the rail industry was deeply restructured worldwide to halt erosion of the sector's share of transportation markets. Restructuring took different forms in different countries, ranging from simple reorganization measures to extreme restructuring -with the private sector increasingly participating in the sector and with the provision of infrastructure separated from the provision of services. The authors argue that regulation of the rail industry cannot remain unaffected by these changes. New regulatory scenarios and issues have emerged. For example, contracts have to be defined for private participation and quality surveillance instruments must be defined. Traditional price controls have to be adapted to, and mechanisms designed to manage and plan infrastructure investments in, the new environment. Restructuring has brought new problems, too. Where licenses have been used, for example, several concessionaires have been unable to meet the objectives spelled out in the concession contract. Contracts should be flexible enough to take account of novel situations that may affect company performance. And yet, for the system to be credible, there cannot be systematic, unjustified deviations from the franchise objectives. Regulation of the sector should be simple and flexible, with license contracts designed to include the private sector and with industry organization adapted to local circumstances. Regulation should be governed by principles that foster competition and market mechanisms, wherever possible. At the same time, it should provide a stable legal and institutional framework for economic activity. Otherwise, regulators should refrain from intervening in the market-unless the goal of economic efficiency (subject to the socially demanded levelof equity) is in jeopardy.Municipal Financial Management,Banks&Banking Reform,Decentralization,Enterprise Development&Reform,Public Sector Economics&Finance,Railways Transport,Banks&Banking Reform,Municipal Financial Management,Water and Industry,Public Sector Economics&Finance

    Analytical Models in Rail Transportation: An Annotated Bibliography

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    Not AvailableThis research has been supported, in part, by the U.S. Department of Transportation under contract DOT-TSC-1058, Transportation Advanced Research Program (TARP)

    Business optimization through automated signaling design

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    M.Ing. (Engineering Management)Abstract: Railway signaling has become pivotal in the development of railway systems over the years. There is a global demand for upgrading signaling systems for improved efficiency. Upgrading signaling systems requires new signaling designs and modifications to adjacent signaling systems. The purpose of this research is to compare manually produced designs with design automation by covering the framework of multiple aspects of railway signaling designs in view of business optimization using computer drawings, programming software language and management of signaling designs. The research focuses on design automation from the preliminary design stage to the detailed design stage with the intention of investigating and resolving a common project challenge of time management. Various autonomous methods are used to seek improvement on the detailed design phase of re-signaling projects. An analysis on the project’s duration, resources and review cycles is conducted to demonstrate the challenges that are faced during the design of a project. Signaling designs are sophisticated and crucial in an ever-changing railway environment. As a result, there is a demand for efficiency and knowledge within railway signaling to achieve successful completion project target dates. A quantitative approach is used to identify the gaps leading to delays and best practices are applied using a comparative analysis to remediate on any snags that may potentially extend the project duration. The results illustrate that the resources required when automating detailed designs are reduced by two thirds for cable plans and book of circuits and reduced by one third for source documents. Successively, the projects benefit with reduced organizational resources, reduced design durations and reduced design review cycles. This research concludes that software integration of the signaling designs due to the efficiency and innovation of the selected computer drawing software and programming software language such as AutoCAD required less resources for computer drawings that are generated using automation tools compared to computer drawings that are generated manually. The resources required when automating the generation of signaling detailed designs are reduced for cable plans, book of circuits and source documents. This means that the business is optimized by utilizing less resources and subsequently delays are reduced during the design stage

    Multi-carrier track capacity allocation in forward and spot markets of freight transport

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    This dissertation addresses multi-carrier, multi-line train scheduling problems for forward and spot markets. Schedules resulting from solution of these train scheduling problems enable carriers to make customer commitments for serving forward contracts and to transport one-off-loads arising on spot markets. A train slot selection model based on multicommodity network flow concepts is developed for determining timetables for use in forward markets and a column generation methodology is proposed for its solution. The model considers needs of both shippers and carriers. The solution approach is embedded in a simulation-based iterative framework, where demand elasticity is explicitly treated. A combinatorial auction-based track capacity allocation framework is introduced to allocate residual track capacity among competing carriers seeking to run additional trains on an as-needed basis. Bid set construction techniques are proposed that allow carriers to express their preferences for track usage. A winner determination problem is formulated, solution of which provides the optimal allocation of track capacity among carriers. The potential benefits of collaborative operation among carriers in both markets were recognized. Collaborative decision-making (CDM) strategies are designed for scheduling trains to serve forward markets. Performances of these strategies are assessed in a carrier collaboration simulation-assignment framework. A train space leasing technique and a CA-based train slot creation approach are proposed to accommodate one-off-loads on previously scheduled and newly formed trains, respectively. Required techniques for bid set construction are developed. A WDP is formulated that seeks the optimal allocation of track access rights to bidders for the given bid sets. Implementation of the resulting train schedules will aid in creating efficient and cost-effective rail transport, resulting in a competitive and green alternative to truck transportation. Additionally, collaboration among competing carriers can lead to the formation of profitable trains that might otherwise have been underutilized and an ability of each carrier to serve a greater share of the freight market. The methodologies were specifically intended for solving large, real-world train scheduling problems

    Collaborative urban transportation : Recent advances in theory and practice

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    We thank the Leibniz Association for sponsoring the Dagstuhl Seminar 16091, at which the work presented here was initiated. We also thank Leena Suhl for her comments on an early version of this work. Finally, we thank the anonymous reviewers for the constructive comments.Peer reviewedPostprin

    Design for Optimized Multi-Lateral Multi-Commodity Markets

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    In this paper, we propose a design for an an economically efficient, optimized, centralized, multi-lateral, periodic commodity market that addresses explicitly three issues: (i) substantial transportation costs between sellers and buyers; (ii) non homogeneous, in quality and nature, commodities; (iii) complementary commodities that have to be traded simultaneously. The model allows sellers to offer their commodities in lots and buyers to explicitly quantify the differences in quality of the goods produced by each individual seller. The model does not presume that products must be shipped through a market hub. We also propose a multi-round auction that enables the implementation of the direct optimized market and approximates the behaviour of the "ideal" direct optimized mechanism. The process allows buyers and sellers to modify their initial bids, including the technological constraints. The proposed market designs are particularly relevant for industries related to natural resources. We present the models and algorithms required to implement the optimized market mechanisms, describe the operations of the multi-round auction, and discuss applications and perspectives. Nous présentons un concept de marché optimisé, centralisé, multilatéral et périodique pour l'acquisition de produits qui traite explicitement les trois aspects suivants: (i) des coûts de transport importants des vendeurs vers les acheteurs; (ii) des produits non homogènes en valeur et qualité; des complémentarités entre les divers produits qui doivent donc être négociés simultanément. Le modèle permet aux vendeurs d'offrir leurs produits groupés en lots et aux acheteurs de quantifier explicitement leur évaluation des lots mis sur le marché par chaque vendeur. Le modèle ne suppose pas que les produits doivent être expédiés par un centre avant d'être livrés. Nous proposons également un mécanisme de tâtonnement à rondes multiples qui approxime le comportement du marché direct optimisé et qui permet de mettre ce dernier en oeuvre. Le processus de tâtonnement permet aux vendeurs et aux acheteurs de modifier leurs mises initiales, incluant les contraintes technologiques. Les concepts proposés sont particulièrement adaptés aux industries reliées aux matières premières. Nous présentons les modèles et algorithmes requis à la mise en oeuvre du marché multi-latéral optimisé, nous décrivons le fonctionnement du processus de tâtonnement, et nous discutons les applications et perspectives reliées à ces mécanismes de marché.Market design, optimized multi-lateral multi-commodity markets, multi-round auctions, Design de marché, marché multi-latéraux optimisés, processus de tâtonnement

    Towards the Internet of Smart Trains: A Review on Industrial IoT-Connected Railways

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    [Abstract] Nowadays, the railway industry is in a position where it is able to exploit the opportunities created by the IIoT (Industrial Internet of Things) and enabling communication technologies under the paradigm of Internet of Trains. This review details the evolution of communication technologies since the deployment of GSM-R, describing the main alternatives and how railway requirements, specifications and recommendations have evolved over time. The advantages of the latest generation of broadband communication systems (e.g., LTE, 5G, IEEE 802.11ad) and the emergence of Wireless Sensor Networks (WSNs) for the railway environment are also explained together with the strategic roadmap to ensure a smooth migration from GSM-R. Furthermore, this survey focuses on providing a holistic approach, identifying scenarios and architectures where railways could leverage better commercial IIoT capabilities. After reviewing the main industrial developments, short and medium-term IIoT-enabled services for smart railways are evaluated. Then, it is analyzed the latest research on predictive maintenance, smart infrastructure, advanced monitoring of assets, video surveillance systems, railway operations, Passenger and Freight Information Systems (PIS/FIS), train control systems, safety assurance, signaling systems, cyber security and energy efficiency. Overall, it can be stated that the aim of this article is to provide a detailed examination of the state-of-the-art of different technologies and services that will revolutionize the railway industry and will allow for confronting today challenges.Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED431C 2016-045Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED341D R2016/012Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; ED431G/01Agencia Estatal de Investigación (España); TEC2013-47141-C4-1-RAgencia Estatal de Investigación (España); TEC2015-69648-REDCAgencia Estatal de Investigación (España); TEC2016-75067-C4-1-

    Efficiency in rail systems through three different approaches and contributions to push the Brazilian rail system toward high performance

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    Tese (Doutorado em Administração) - Universidade Federal do Rio de Janeiro, Rio de Janeiro, 2019Inclui bibliografiaThis research investigates the efficiency of the Brazilian rail cargo system (SFBC, acronym in Portuguese). The importance of the performance of a rail system to the logistics of goods in countries with large territorial dimensions is recognized. However, its role is secondary in Brazil compared to road transport, representing high economic and environmental costs. SFBC is dedicated to the export of mineral and agricultural bulk where it has a significant capacity for insertion. Meanwhile, the SFBC has an insignificant participation in the internal distribution of goods, which is mostly done in highways, including on longer routes. Consequently, the transport sector in Brazil emits twice as much CO2 from buming fuels than the world average. SFBC presents characteristics of a medium performance scenario. The performance of the operators is heterogeneous, benchmarking is an outlier, the average efficiency is low, and the average idleness of the sections is high. To discuss the conditions to achieve a high performance scenario is the main contribution of this thesis. Three researches were done to address this issue. The first one is dedicated to estimate the efficiency of the railway concessionaires in Brazil between 2010-2014 by using Data Envelopment Analysis. In a second stage, the significance of selected variables was assessed through Bootstrap Truncated Regression, including the type of the use of the railway track (shared or monopoly), a gap in the literature. The operators were grouped according to the efficiency scores and the type of returns to scale, and measures to increase the efficiency of the clusters were discussed. The second research has the purpose to explain the heterogeneity found in the average efficiency of the different railway systems in the world, the object of researches done between 2000-2016, through a meta-analysis carried out for the first time onj railways. For greater robustness, Leave-One-Out-Cross-Validation and VVeighted Regression were applied. Public policies induding diversification of services and models for assessing efficiency by regulatory agencies were discussed. The third research is devoted to the efficiency of the SFBC raílway sections and identifies the significant conditions for high and low performance scenarios by combining the Technique for Order of Preference by Similarity to Ideal Solution and a differential evolution algorithm for estimating the weights of variables in optimized scenarios, another gap in the literature. In a second stage, the significance of the variables selected was evaluated. The research shows that the public manager should push the rail companies toward the transportation of any type of cargo, the diversification of services, the centralized control of the operation, and the sharing of the railway track. The competition and diversifìcation are significant for high performance.A pesquisa investiga a eficiência do Sistema Ferroviário Brasileiro de Cargas (SFBC). É reconhecida a importância do desempenho de um sistema ferroviário para a logística de mercadorias em países de grandes dimensões territoriais. Todavia, seu papel é secundário no Brasil frente ao transporte rodoviário, representando custos econômicos e ambientais excedentes. O SFBC se mantém dedicado à exportação de granéis sólidos minerais e agrícolas onde apresenta significativa capacidade de inserção, enquanto é inexpressiva sua participação na distribuição interna de bens, majoritariamente realizada pelo setor rodoviário, inclusive em rotas mais longas. Assim, o setor de transporte no Brasil emite o dobro de CO2 pela queima de combustíveis do que a média mundial. O SFBC apresenta características de um cenário de média performance. O desempenho dos operadores é heterogêneo, o benchmarking é um outlier, a eficiência média é baixa e a ociosidade média das seções é alta. Discutir as condições para alcançar um cenário de alta performance é a principal contribuição da tese. Para atingir esse objetivo, foram realizadas três pesquisas. A primeira se dedica à eficiência dos concessionários ferroviários no Brasil no período 2010-2014, com o uso de Data Envelopment Analysis. Num segundo estágio, através de Bootstrap Truncated Regression, foi avaliada a significância de variáveis selecionadas, incluindo o tipo de uso da via, gap da literatura. Os operadores foram agrupados segundo os resultados de eficiência e o tipo de retornos de escala das operações e medidas para o aumento da eficiência dos clusters foram discutidas. A segunda pesquisa tem por objetivo explicar a heterogeneidade encontrada na eficiência média de diversos sistemas ferroviários no mundo, objeto de pesquisas realizadas entre 2000-2016, através de uma metanálise conduzida pela primeira vez em ferrovias. Para maior robutez, Leave-One-Out-Cross-Validation e Weighted Regression foram utilizadas. Políticas públicas incluindo diversificação e modelos de avaliação de eficiência por órgãos reguladores foram comentadas. A terceira pesquisa se dedica à eficiência das seções ferroviárias e identifica as condições significativas para cenários de alta e baixa performance através da combinação de Technique for Order of Preference by Similarity to Ideal Solution e de um algoritmo de evolução diferencial para estimar os pesos de variáveis em cenários otimizados, gap da literatura. Num segundo estágio, a significância de variáveis selecionadas foi avaliada. A pesquisa mostra que o gestor público deve empurrar as empresas para o transporte de todo o tipo de carga, a diversificação de serviços, o controle centralizado da operação e o compartilhamento da via. A competição e a diversificação são significativas para a alta performance
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