27 research outputs found

    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)

    Удосконалення взаємодії поїздоутворення на технічних станціях з графіком руху поїздів

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    It is shown that one of the measures to ensure the effectiveness and reliability of the schedule is use of flexible weighted norms. As a result of working conditions research of railway yards at sending of trains using flexible standards of weight and length of train will be found that flexible train formation management will reduce the interoperable down time, including downtime of trains awaiting departure at 60-80%.Irregularity reducing favorably affects both their performance and the performance of those companies that it serves. Therefore, in order to keep the constant movement size on the assumption of uniform departure of trains is advisable to reduce the minimum, or increase the maximum norm. Implementation of freight trains movement technology according to schedule is better starting with sites and directions with stable train flows. Показано, что одним из способов обеспечения эффективности и надежности графика движения является использование гибких весовых норм. В результате проведенных исследований условий работы сортировочных станций при отправлении поездов с использованием гибких норм массы и длины составов, установлено, что гибкое управление поездообразованием позволит сократить межоперационные простой, в том числе простой составов в ожидании отправления на 60–80 %.Показано, що одним із заходів забезпечення ефективності і надійності графіка руху є використання гнучких вагових норм. В результаті проведених досліджень умов роботи сортувальних станцій при відправленні поїздів з використанням гнучких норм маси і довжини складів, встановлено, що гнучке управління поїздоутворенням дозволить скоротити міжопераційні простої, в тому числі простої составів в очікуванні відправлення на 60–80 %

    A Study on the Practical Carrying Capacity of Large High-Speed Railway Stations considering Train Set Utilization

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    Methods for solving the carrying capacity problem for High-Speed Railways (HSRs) have received increasing attention in the literature in the last few years. As important nodes in the High-Speed Railway (HSR) network, large stations are usually the carrying capacity bottlenecks of the entire network due to the presence of multiple connections in different directions and the complexity of train operations at these stations. This paper focuses on solving the station carrying capacity problem and considers train set utilization constraints, which are important influencing factors that have rarely been studied by previous researchers. An integer linear programming model is built, and the CPLEX v12.2 software is used to solve the model. The proposed approach is tested on a real-world case study of the Beijing South Railway Station (BS), which is one of the busiest and most complex stations in China. Studies of the impacts of different train set utilization constraints on the practical station carrying capacity are carried out, and some suggestions are then presented for enhancing the practical carrying capacity. Contrast tests indicate that both the efficiency of the solving process and the quality of the solution show huge breakthroughs compared with the heuristic approach

    Development of a maintenance possession scheduler for a railway

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    Thesis (MEng)--Stellenbosch University, 2022.ENGLISH SUMMARY: Maintenance of rail infrastructure is an important element in rail operations in order to keep tra c moving. However, maintenance causes infrastructure to be taken out of service, which impacts tra c ow. In this study, the requirements of a maintenance possession scheduler for a South African application was investigated, and a proposed solution was subsequently developed. The main objective of the scheduler was to minimise the deviation of the train service on a subset of rail infrastructure while ensuring that the required maintenance is done. To achieve this, a literature study was done on a number of themes, which include an overview of the local railway operator with a look at the role of industrial engineering as a function in the railway operator business, railway infrastructure and operations, planning of railway operations, and maintenance in the context of rail operations. The topic of possession scheduling was then studied; the previous themes helped the researcher to learn the bigger picture while understanding possession scheduling is critical for this study. Past and recent works were studied and research areas and trends were synthesised, including time span of possession scheduling in optimisation models, and whether it was done on microscopic, mesoscopic or macroscopic level. The various optimisation objectives formulated by researchers were also noted, among other subthemes. An application case was identi ed as the railway infrastructure between Bellville and Wellington in the Western Cape province of South Africa. A novel mixed-integer linear programming model was formulated for this case and implemented in Cplex, after which it was validated. The model can do possession scheduling for 24 hours on a microscopic level. Finally, several experiments were conducted to investigate the performance and results of the model. It was found that the model delivered optimal results in less than eight minutes, which makes it a feasible maintenance possession scheduler for day-to-day work in the immediate planning horizon.AFRIKAANS OPSOMMING: Instandhouding van spoorinfrastruktuur is 'n belangrike element in spoorwegoperasies ten einde verkeervloei te verseker. Instandhouding veroorsaak egter dat infrastruktuur uit diens geneem word wat verkeer weer belemmer. In hierdie studie was die vereistes van 'n besitskeduleerder vir instandhouding vir 'n Suid-Afrikaanse toepassing ondersoek, en die voorgestelde oplossing was daarna ontwikkel. Die hoofdoelwit van die skeduleerder was om die afwykings van die trein diens te minimeer op 'n gedeelte van spoorinfrastruktuur terwyl verseker word dat die nodige instandhouding gedoen word. Om dit te bereik is 'n literatuurstudie op 'n aantal temas gedoen. Dit sluit in 'n oorsig van die plaaslike spoorwegoperateur en die rol wat bedryfsingenieurswese as funksie daarin vervul, spoorweginfrastruktuur en operasies, en instandhouding in die konteks van spoorwegoperasies. Die onderwerp van besitskedulering was daarna bestudeer; die vorige temas het die navorser gehelp om die groter prentjie te verstaan, terwyl die studie van besitskedulering kritiek was vir hierdie studie. Navorsingswerk uit die verlede asook onlangse werk was bestudeer en navorsingsareas en tendense is deur sintese bepaal. Dit sluit in die tydsduur van besitskedulering in optimeringsmodelle en of dit op mikro-, meso- of makroskopiese vlak gedoen word. Die verskillende optimeringsdoelwitte wat navorsers formuleer het is ook waargeneem, asook met ander subtemas. 'n Gevallestudie vir toepassing van 'n besitskeduleerder vir instandhouding is identi seer as die spoorweginfrastruktuur tussen Bellville enWellington in die Wes-Kaap provinsie van Suid-Afrika. 'n Nuwe gemengde heeltal-line^ere programmeringmodel was geformuleer vir hierdie gevallestudie en in Cplex implementeer, waarna dit gevalideer is. Die model kan besitskedulering vir 24 uur doen op mikrovlak. Verskeie eksperimente is uiteindelik uitgevoer om die prestasie en resultate van die model waar te neem. Dit is bevind dat die model optimale resultate in minder as agt minute kon lewer, wat dit 'n aanvaarbare instandhouding besitskeduleerder maak vir dag-tot-dag werk in die nabye beplanningshorison.Master

    A Study on the Practical Carrying Capacity of Large High-Speed Railway Stations considering Train Set Utilization

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    Methods for solving the carrying capacity problem for High-Speed Railways (HSRs) have received increasing attention in the literature in the last few years. As important nodes in the High-Speed Railway (HSR) network, large stations are usually the carrying capacity bottlenecks of the entire network due to the presence of multiple connections in different directions and the complexity of train operations at these stations. This paper focuses on solving the station carrying capacity problem and considers train set utilization constraints, which are important influencing factors that have rarely been studied by previous researchers. An integer linear programming model is built, and the CPLEX v12.2 software is used to solve the model. The proposed approach is tested on a real-world case study of the Beijing South Railway Station (BS), which is one of the busiest and most complex stations in China. Studies of the impacts of different train set utilization constraints on the practical station carrying capacity are carried out, and some suggestions are then presented for enhancing the practical carrying capacity. Contrast tests indicate that both the efficiency of the solving process and the quality of the solution show huge breakthroughs compared with the heuristic approach

    Network revenue management game in the rail freight industry

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    PhD ThesisThe study aims to design the optimal track access tariff to coordinate the relationship between an Infrastructure Manager (IM) and a Freight Operating Company (FOC) in a vertical separated railway system. In practice, the IM takes advantage of leader position in determining the prices to unilaterally maximise its profits without the collaboration with the FOC, which leads to a sub-optimal situation. The interaction between the IM and the FOC is modelled as a network-based Stackelberg game. First, a rigorous bilevel optimisation model is presented that determines the best prices for an IM to maximise its profits without any collaboration with the FOC. The lower level of the bilevel model contains binary integer variables representing the FOC’s choices on the itineraries, which is a challenging optimisation problem not resolved in the literature. The study proposes a uniquely designed solution method involving both gradient search and local search to successfully solve the problem. Secondly, an inverse programming model is developed to determine the IM’s prices to maximise the system profit and achieve global optimality. A Fenchel cutting plane based algorithm is developed to solve the inverse optimisation model. Thirdly, a government subsidy based pricing mechanism is designed. To identify the optimal amount of subsidy, a double-layer gradient search and local search method is developed. The proposed mechanism can lead to the global optimality and ensure that the IM and the FOC are better off than the above two scenarios. Numerical cases based on the data from the UK rail freight industry are conducted to validate the models and algorithms. The results reveal that both the optimal prices obtained via inverse optimisation and the subsidy contract outperform the non-cooperation case in the current industrial practice; and that the cooperation between the IM and the FOC in determining track access tariff is better than non-cooperation

    Affectation des locomotives et des wagons aux trains de passagers

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    A survey of optimization models for train routing and scheduling -- Routing problems -- Scheduling problems -- Simultaneous locomotive and car assignment at VIA Rail Canada -- Solution methodology -- Extensions -- Computational experiments -- A benders decomposition approach for the locomotive and car assignment problem -- Benders decomposition -- Algorithmic refinements -- Computational experiments -- Simultaneous assigment of locomotives and cars to passenger trains -- A basic model -- Solution methodology -- Computational considerations -- Computational experimentation

    Mathematical programming models to design and analyse efficient and robust raiway freight transport networks

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    (English) Searching to achieve an ambitious reduction in greenhouse gas emissions, the European Union has set as a goal a modal shift in freight transport of 30\% by rail or waterborne for the near future. The increasing efforts of many governments to intensify rail freight transport often must face the difficulties involved in improving both infrastructure and rail operations. Moreover, infrastructure management and business operations usually correspond to different entities with highly contradictory economic interests. Making progress on the reliability of the railway network is one of the main factors to be considered to make the use of the train more attractive as a means of transport for industry. Also, focusing on shippers' response to road and rail competition and the role of different rail undertakings competing with each other may help boost the use of rail for freight transport. Seeking to reinforce these two goals, this thesis introduces two independent mathematical optimisation models, which may also be complementary, and which have been developed under a common conceptual framework of data structures and variables to guarantee their compatibility. The first model is a mathematical programming-based design model for evaluating the impact on a mixed railway network from proposals for infrastructure improvement and capacity expansion that are oriented mainly toward increasing freight transportation. The model has been applied to extend elements of an existing mixed railway network, perform relatively less costly actions on the network, and enhance capacity by adding new blocking/control systems at specific locations. These aspects are usually not considered in models for regional planning. Rather than a model whose sole focus is on railway capacity expansion, this approach combines capacity-expansion with network design. Because the way investments generate returns to the freight transportation system is of utmost relevance for these types of problems, this model is based on the efficient frontier between investment and operating costs. The second model is a combined model for jointly evaluating the modal split road-rail, and the resulting railway freight flows on the railway network. This combined modal split-traffic assignment model is addressed to the case when a modal split based on a random utility model is available, and some of its coefficients may present a non-negligible variability. To this end, after the initial deterministic formulation, a robust counterpart of the model is developed. The model, formulated as a non-linear integer programming problem, is oriented to a multi-carrier environment and includes constraints to consider the interactions between the different types of flows on the railway network, allowing a detailed evaluation of the cost types of the carriers and the network capacity. An algorithmic solution based on the outer approximation method is shown to provide accurate solutions in a reasonable computational time for the robust and non-robust versions of the model. Examples centred on a section of the Trans-European Transport Network, the TEN-T Core network corridors, are reported to test the applicability of the models. Results show the effectiveness of both models. The design model can be a helpful tool for analysing the impact infrastructure investments may have on operating costs, where (implicit) capacity limitations in the scenarios to be evaluated may necessarily be taken into account. At the same time, it can be complemented with the combined modal split-traffic assignment model by assessing the possible shippers' response to the different railway carriers' services competing with each other and the road.(Español) Tratando de lograr una significativa y ambiciosa reducción de las emisiones de gases de efecto invernadero, la Unión Europea se ha marcado como objetivo que los modos de transporte de mercancías alternativos a la carretera, como el ferrocarril o la navegación fluvial, alcancen una cuota del 30% sobre el total de mercancías transportadas por tierra en Europa en los próximos años. Los crecientes esfuerzos que llevan a cabo los diferentes gobiernos se enfrentan con demasiada frecuencia con las dificultades que suponen mejorar de forma simultánea infraestructura y operaciones ferroviarias, habitualmente gestionados por entes diferentes con intereses económicos enfrentados. Mejorar la fiabilidad de la red ferroviaria es uno de los principales factores a tener en cuenta para hacer más atractivo el uso del tren como medio de transporte para la industria. Por otro lado, centrarse en los criterios que pueden llevar a las empresas a elegir entre carretera o tren, y en el papel que juegan las diferentes compañías ferroviarias en esta elección, compitiendo entre sí, puede ayudar a incrementar el uso del tren para el transporte de mercancías. Con la idea de reforzar estos dos objetivos, este trabajo de tesis presenta dos modelos matemáticos de optimización, independientes pero a la vez complementarios, y desarrollados bajo un marco conceptual de estructuras de datos y variables común para garantizar su compatibilidad. El primer modelo es un modelo de diseño basado en programación matemática para evaluar el impacto que pueden tener, sobre una red ferroviaria de uso mixto, propuestas de mejora de la infraestructura y de ampliación de la capacidad dirigidas principalmente a incrementar el uso del tren para el transporte de mercancías. El modelo se ha orientado a la modificación de elementos de una red ferroviaria de uso mixto existente, proponiendo intervenciones en la red relativamente poco costosas, y aumentando la capacidad añadiendo nuevos sistemas de bloqueo y control en ubicaciones específicas. Para este tipo de problemas, es de la máxima relevancia la manera en que las inversiones generan retornos al sistema de transporte ferroviario. Por eso, este modelo está basado en el óptimo equilibrio entre la inversión y los costes de operación. El segundo modelo es un modelo combinado para evaluar de forma conjunta el reparto modal entre carretera y tren, y los flujos de mercancías en la red ferroviaria resultantes. Este modelo está enfocado hacia aquellas situaciones en que hay un modelo de utilidad aleatoria disponible, pero algunos de sus coeficientes pueden presentar una variabilidad que no debe ser ignorada. Con esta finalidad, tras la formulación inicial del modelo determinístico se presenta una versión robusta de la formulación. El modelo, formulado como un problema de programación no lineal entera, está enfocado hacia un entorno en el que conviven (y compiten) diferentes compañías ferroviarias. Se detalla un algoritmo para resolver el modelo, basado en el método de aproximaciones externas, que permite obtener soluciones precisas con un tiempo computacional razonable, tanto para la versión determinística como para la versión robusta. Ejemplos basados en una sección de la Red Trans-Europea de Transporte (TEN-T por sus siglas en inglés) permiten validar la aplicabilidad y eficacia de los modelos. El modelo de diseño puede ser una herramienta útil para analizar el impacto que las inversiones en infraestructura pueden tener en los costes de operación, teniendo en cuenta las limitaciones de capacidad que existen en los escenarios evaluados. De la misma forma, se puede complementar este análisis con el modelo combinado de reparto modal y asignación de flujos, en el que se puede comprobar la posible respuesta de las empresas que requieren transportar sus productos ante los diferentes servicios ofrecidos por las compañías ferroviarias compitiendo entre si, y compitiendo con la carretera.Estadística i investigació operativ

    Mathematical programming models to design and analyse efficient and robust raiway freight transport networks

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    (English) Searching to achieve an ambitious reduction in greenhouse gas emissions, the European Union has set as a goal a modal shift in freight transport of 30\% by rail or waterborne for the near future. The increasing efforts of many governments to intensify rail freight transport often must face the difficulties involved in improving both infrastructure and rail operations. Moreover, infrastructure management and business operations usually correspond to different entities with highly contradictory economic interests. Making progress on the reliability of the railway network is one of the main factors to be considered to make the use of the train more attractive as a means of transport for industry. Also, focusing on shippers' response to road and rail competition and the role of different rail undertakings competing with each other may help boost the use of rail for freight transport. Seeking to reinforce these two goals, this thesis introduces two independent mathematical optimisation models, which may also be complementary, and which have been developed under a common conceptual framework of data structures and variables to guarantee their compatibility. The first model is a mathematical programming-based design model for evaluating the impact on a mixed railway network from proposals for infrastructure improvement and capacity expansion that are oriented mainly toward increasing freight transportation. The model has been applied to extend elements of an existing mixed railway network, perform relatively less costly actions on the network, and enhance capacity by adding new blocking/control systems at specific locations. These aspects are usually not considered in models for regional planning. Rather than a model whose sole focus is on railway capacity expansion, this approach combines capacity-expansion with network design. Because the way investments generate returns to the freight transportation system is of utmost relevance for these types of problems, this model is based on the efficient frontier between investment and operating costs. The second model is a combined model for jointly evaluating the modal split road-rail, and the resulting railway freight flows on the railway network. This combined modal split-traffic assignment model is addressed to the case when a modal split based on a random utility model is available, and some of its coefficients may present a non-negligible variability. To this end, after the initial deterministic formulation, a robust counterpart of the model is developed. The model, formulated as a non-linear integer programming problem, is oriented to a multi-carrier environment and includes constraints to consider the interactions between the different types of flows on the railway network, allowing a detailed evaluation of the cost types of the carriers and the network capacity. An algorithmic solution based on the outer approximation method is shown to provide accurate solutions in a reasonable computational time for the robust and non-robust versions of the model. Examples centred on a section of the Trans-European Transport Network, the TEN-T Core network corridors, are reported to test the applicability of the models. Results show the effectiveness of both models. The design model can be a helpful tool for analysing the impact infrastructure investments may have on operating costs, where (implicit) capacity limitations in the scenarios to be evaluated may necessarily be taken into account. At the same time, it can be complemented with the combined modal split-traffic assignment model by assessing the possible shippers' response to the different railway carriers' services competing with each other and the road.(Español) Tratando de lograr una significativa y ambiciosa reducción de las emisiones de gases de efecto invernadero, la Unión Europea se ha marcado como objetivo que los modos de transporte de mercancías alternativos a la carretera, como el ferrocarril o la navegación fluvial, alcancen una cuota del 30% sobre el total de mercancías transportadas por tierra en Europa en los próximos años. Los crecientes esfuerzos que llevan a cabo los diferentes gobiernos se enfrentan con demasiada frecuencia con las dificultades que suponen mejorar de forma simultánea infraestructura y operaciones ferroviarias, habitualmente gestionados por entes diferentes con intereses económicos enfrentados. Mejorar la fiabilidad de la red ferroviaria es uno de los principales factores a tener en cuenta para hacer más atractivo el uso del tren como medio de transporte para la industria. Por otro lado, centrarse en los criterios que pueden llevar a las empresas a elegir entre carretera o tren, y en el papel que juegan las diferentes compañías ferroviarias en esta elección, compitiendo entre sí, puede ayudar a incrementar el uso del tren para el transporte de mercancías. Con la idea de reforzar estos dos objetivos, este trabajo de tesis presenta dos modelos matemáticos de optimización, independientes pero a la vez complementarios, y desarrollados bajo un marco conceptual de estructuras de datos y variables común para garantizar su compatibilidad. El primer modelo es un modelo de diseño basado en programación matemática para evaluar el impacto que pueden tener, sobre una red ferroviaria de uso mixto, propuestas de mejora de la infraestructura y de ampliación de la capacidad dirigidas principalmente a incrementar el uso del tren para el transporte de mercancías. El modelo se ha orientado a la modificación de elementos de una red ferroviaria de uso mixto existente, proponiendo intervenciones en la red relativamente poco costosas, y aumentando la capacidad añadiendo nuevos sistemas de bloqueo y control en ubicaciones específicas. Para este tipo de problemas, es de la máxima relevancia la manera en que las inversiones generan retornos al sistema de transporte ferroviario. Por eso, este modelo está basado en el óptimo equilibrio entre la inversión y los costes de operación. El segundo modelo es un modelo combinado para evaluar de forma conjunta el reparto modal entre carretera y tren, y los flujos de mercancías en la red ferroviaria resultantes. Este modelo está enfocado hacia aquellas situaciones en que hay un modelo de utilidad aleatoria disponible, pero algunos de sus coeficientes pueden presentar una variabilidad que no debe ser ignorada. Con esta finalidad, tras la formulación inicial del modelo determinístico se presenta una versión robusta de la formulación. El modelo, formulado como un problema de programación no lineal entera, está enfocado hacia un entorno en el que conviven (y compiten) diferentes compañías ferroviarias. Se detalla un algoritmo para resolver el modelo, basado en el método de aproximaciones externas, que permite obtener soluciones precisas con un tiempo computacional razonable, tanto para la versión determinística como para la versión robusta. Ejemplos basados en una sección de la Red Trans-Europea de Transporte (TEN-T por sus siglas en inglés) permiten validar la aplicabilidad y eficacia de los modelos. El modelo de diseño puede ser una herramienta útil para analizar el impacto que las inversiones en infraestructura pueden tener en los costes de operación, teniendo en cuenta las limitaciones de capacidad que existen en los escenarios evaluados. De la misma forma, se puede complementar este análisis con el modelo combinado de reparto modal y asignación de flujos, en el que se puede comprobar la posible respuesta de las empresas que requieren transportar sus productos ante los diferentes servicios ofrecidos por las compañías ferroviarias compitiendo entre si, y compitiendo con la carretera.Postprint (published version

    CATRIN (Cost Allocation of TRansport INfrastructure cost), Deliverable 8 - Rail Cost Allocation for Europe

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