9,737 research outputs found

    Drawing the line: balancing the spatial requirements of customer and contractor in occupied refurbishment

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    In planning the refurbishment of railway stations the spatial needs of the contractor and ofthe ongoing business stakeholders have to be balanced. A particular concern is thedisruptive effect of construction works upon pedestrian movement.RaCMIT (Refurbishment and Customer Movement Integration Tool) is a research projectaimed at addressing this problem through combining the knowledge of the client projectmanager, the construction planner and the pedestrian modelling expert.The objective of the research is to develop a decision protocol (based on problemsencountered in two case studies) facilitating optimisation of overall project value to theclient?s business.Research observations as well as current literature suggest that:? for overall decision-making, opportunities may be lost (under current practice) forminimising joint project cost/revenue disruption and? for spatial decision-making, temporary station configuration during construction(and not just overall pedestrian capacity) is a significant variable for both businessand safety outcomes. In planning the refurbishment of railway stations the spatial needs of the contractor and ofthe ongoing business stakeholders have to be balanced. A particular concern is thedisruptive effect of construction works upon pedestrian movement.RaCMIT (Refurbishment and Customer Movement Integration Tool) is a research projectaimed at addressing this problem through combining the knowledge of the client projectmanager, the construction planner and the pedestrian modelling expert.The objective of the research is to develop a decision protocol (based on problemsencountered in two case studies) facilitating optimisation of overall project value to theclient?s business.Research observations as well as current literature suggest that:? for overall decision-making, opportunities may be lost (under current practice) forminimising joint project cost/revenue disruption and? for spatial decision-making, temporary station configuration during construction(and not just overall pedestrian capacity) is a significant variable for both businessand safety outcomes

    Balancing operating revenues and occupied refurbishment costs 1: problems of defining project success factors and selecting site planning methods

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    In planning the refurbishment of railway stations the spatial needs of the contractor and of the ongoing business stakeholders have to be balanced. A particular concern is the disruptive effect of construction works upon pedestrian movement. RaCMIT (Refurbishment and Customer Movement Integration Tool) was a research project aimed at addressing this problem. The objective of the research was to develop a decision protocol facilitating optimisation of overall project value to the client's business. This paper (the first of two) presents a framework for considering public disruption in occupied refurbishment using two case studies in large railway stations as examples. It briefly describes new tools which (combined with existing techniques) assist decision making in the management of disruption. It links strategic with sitebased decision making and suggests how public disruption may be treated as a variable to be jointly optimised along with traditional criteria such as time, cost and quality. Research observations as well as current literature suggest that for overall decision-making, opportunities may be lost (under current practice) for minimising joint project cost/revenue disruption, and, for spatio-temporal site decision-making, effective and efficient tools now exist to model both sides of the construction site boundary

    Issues on simulation of the railway rolling stock operation process – a system and literature review

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    Railway traffic simulation, taking into account operation and maintenance conditions, is not a new issue in the literature. External effects in such networks (eg. level crossings) were not taken into account in studies. The used models do not take into account sufficiently the process of degradation and recovery of the network. From the technical side, currently carried out simulations are made using similar approaches and techniques as in the initial stage of research. Well-established work in this area could be the basis for evaluation of new solutions. However, the progress in simulation tools during the last years, especially in performance and programming architecture, attempt to create a modern simulation tool. In the paper were presented the main assumptions for the evaluated event-based simulation method, with application to stiff-track transportation network

    A simulation study on the potential of moving urban freight by a cross-city railway line.

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    This paper analyses the scope for moving urban freight through rail by evaluating the utilisation levels of the Cross-City railway line in The United Kingdom (UK), running between Lichfield Trent Valley and Birmingham New Street. A simulation model of the railway system was built and implemented using SIMUL8 computer software. The results from the simulation model suggest that the railway line is being under-utilised. These low utilisation levels of the line presented a case to propose three scenarios that has the potential to carry urban freight by rail through Lichfield Trent Valley to Birmingham New Street Station. The total number of services operated on the line is varied between different scenarios. The proposed three scenarios could not only exploit the existing railway infrastructure by improving the utilisation levels of the currently operating railway line, but also proved to reduce an amount of green-house gases (GHGs) emissions that are caused by heavy goods vehicles (HGVs) moving on the road. After simulating all the proposed scenarios in the SIMUL8 simulation software and analysing the results, scenario number 3 seemed to be the best replacement to the actual system as it presents a case to increase the number of train services running per day by in the line by 108 and causing a drastic improvement in the utilisation levels by an increase of 341.71% to that of the actual system. This proposed system has the potential to eliminate 5400 HGVs moving on the road per day that causes a reduction of CO 2 gas by approximately 5.4%. All the scenarios presented in the study assures a sustainable method to move the urban freight by rail that has the potential to reduce congestion and emissions in the West Midlands region of the United Kingdom (UK)

    Passenger Flows in Underground Railway Stations and Platforms, MTI Report 12-43

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    Urban rail systems are designed to carry large volumes of people into and out of major activity centers. As a result, the stations at these major activity centers are often crowded with boarding and alighting passengers, resulting in passenger inconvenience, delays, and at times danger. This study examines the planning and analysis of station passenger queuing and flows to offer rail transit station designers and transit system operators guidance on how to best accommodate and manage their rail passengers. The objectives of the study are to: 1) Understand the particular infrastructural, operational, behavioral, and spatial factors that affect and may constrain passenger queuing and flows in different types of rail transit stations; 2) Identify, compare, and evaluate practices for efficient, expedient, and safe passenger flows in different types of station environments and during typical (rush hour) and atypical (evacuations, station maintenance/ refurbishment) situations; and 3) Compile short-, medium-, and long-term recommendations for optimizing passenger flows in different station environments

    Dynamic railway junction rescheduling using population based ant colony optimisation

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    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Efficient rescheduling after a perturbation is an important concern of the railway industry. Extreme delays can result in large fines for the train company as well as dissatisfied customers. The problem is exacerbated by the fact that it is a dynamic one; more timetabled trains may be arriving as the perturbed trains are waiting to be rescheduled. The new trains may have different priorities to the existing trains and thus the rescheduling problem is a dynamic one that changes over time. The aim of this research is to apply a population-based ant colony optimisation algorithm to address this dynamic railway junction rescheduling problem using a simulator modelled on a real-world junction in the UK railway network. The results are promising: the algorithm performs well, particularly when the dynamic changes are of a high magnitude and frequency

    Perspectives on subnational carbon and climate footprints: A case study of Southampton, UK

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    Sub-national governments are increasingly interested in local-level climate change management. Carbon- (CO2 and CH4) and climate-footprints—(Kyoto Basket GHGs) (effectively single impact category LCA metrics, for global warming potential) provide an opportunity to develop models to facilitate effective mitigation. Three approaches are available for the footprinting of sub-national communities. Territorial-based approaches, which focus on production emissions within the geo-political boundaries, are useful for highlighting local emission sources but do not reflect the transboundary nature of sub-national community infrastructures. Transboundary approaches, which extend territorial footprints through the inclusion of key cross boundary flows of materials and energy, are more representative of community structures and processes but there are concerns regarding comparability between studies. The third option, consumption-based, considers global GHG emissions that result from final consumption (households, governments, and investment). Using a case study of Southampton, UK, this chapter develops the data and methods required for a sub-national territorial, transboundary, and consumption-based carbon and climate footprints. The results and implication of each footprinting perspective are discussed in the context of emerging international standards. The study clearly shows that the carbon footprint (CO2 and CH4 only) offers a low-cost, low-data, universal metric of anthropogenic GHG emission and subsequent management

    A review of modelling and optimisation methods applied to railways energy consumption

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    [EN] Railways are a rather efficient transport mean, and yet there is increasing interest in reducing their energy consumption and making them more sustainable in the current context of climate change. Many studies try to model, analyse and optimise the energy consumed by railways, and there is a wide diversity of methods, techniques and approaches regarding how to formulate and solve this problem. This paper aims to provide insight into this topic by reviewing up to 52 papers related to railways energy consumption. Two main areas are analysed: modelling techniques used to simulate train(s) movement and energy consumption, and optimisation methods used to achieve more efficient train circulations in railway networks. The most used methods in each case are briefly described and the main trends found are analysed. Furthermore, a statistical study has been carried out to recognise relationships between methods and optimisation variables. It was found that deterministic models based on the Davis equation are by far (85% of the papers reviewed) the most common in terms of modelling. As for optimisation, meta-heuristic methods are the preferred choice (57.8%), particularly Genetic Algorithms.Martínez Fernández, P.; Villalba Sanchis, I.; Yepes, V.; Insa Franco, R. (2019). A review of modelling and optimisation methods applied to railways energy consumption. Journal of Cleaner Production. 222:153-162. https://doi.org/10.1016/j.jclepro.2019.03.037S15316222
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