28,392 research outputs found

    Assessment of the worthwhileness of efficient driving in railway systems with high-receptivity power supplies

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    Eco-driving is one of the most important strategies for significantly reducing the energy consumption of railways with low investments. It consists of designing a way of driving a train to fulfil a target running time, consuming the minimum amount of energy. Most eco-driving energy savings come from the substitution of some braking periods with coasting periods. Nowadays, modern trains can use regenerative braking to recover the kinetic energy during deceleration phases. Therefore, if the receptivity of the railway system to regenerate energy is high, a question arises: is it worth designing eco-driving speed profiles? This paper assesses the energy benefits that eco-driving can provide in different scenarios to answer this question. Eco-driving is obtained by means of a multi-objective particle swarm optimization algorithm, combined with a detailed train simulator, to obtain realistic results. Eco-driving speed profiles are compared with a standard driving that performs the same running time. Real data from Spanish high-speed lines have been used to analyze the results in two case studies. Stretches fed by 1 Ă— 25 kV and 2 Ă— 25 kV AC power supply systems have been considered, as they present high receptivity to regenerate energy. Furthermore, the variations of the two most important factors that affect the regenerative energy usage have been studied: train motors efficiency ratio and catenary resistance. Results indicate that the greater the catenary resistance, the more advantageous eco-driving is. Similarly, the lower the motor efficiency, the greater the energy savings provided by efficient driving. Despite the differences observed in energy savings, the main conclusion is that eco-driving always provides significant energy savings, even in the case of the most receptive power supply network. Therefore, this paper has demonstrated that efforts in improving regenerated energy usage must not neglect the role of eco-driving in railway efficiency

    Assessment of energy and emissions saving solutions in urban rail-based transport systems

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    Global warming and climate change are indisputable theories. Since the Industrial Revolution, the mean temperature of the planet has increased by 1°C. Now, temperatures are approaching a higher stage of +1.5°C and the attention is on both CO2 emissions and energy consumption. Transportation is a major component of the environmental impact, accounting for approximately 30% of air pollution and energy consumption. Due to the rapid urbanization in the EU, with an estimated 74.3% of the population living in cities, forecasted to rise to 80% by 2050, urban mobility is dramatically increasing its relevance. Therefore, a reduction in energy consumption and pollutant emissions is a crucial factor to consider in developing urban transportation and particularly rail-based systems, able to provide energy saving transport services by improving urban environment. Several methods and techniques are under development to improve the energy performance of Light Rail Transport (LRT), which spread from different typologies of power supply to improving energy efficiency. The purpose of this paper is to start from the last developments and innovative energy sources for LRT systems. The focus is on two parts: a) trams running on Hydrogen in parallel with on board batteries with energy saving control techniques, b) potential renewable energy sources to meet power demand. The comparison is with traditional power sources and equipment (e.g. Catenary-based). The methods, based on selected indicators, are under development and test by calculations and simulations with reference to the case study of the new tramlines in the city of Brescia (Italy)

    Climate Action In Megacities 3.0

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    "Climate Action in Megacities 3.0" (CAM 3.0) presents major new insights into the current status, latest trends and future potential for climate action at the city level. Documenting the volume of action being taken by cities, CAM 3.0 marks a new chapter in the C40-Arup research partnership, supported by the City Leadership Initiative at University College London. It provides compelling evidence about cities' commitment to tackling climate change and their critical role in the fight to achieve global emissions reductions

    Transport in developing countries and climate policy: suggestions for a Copenhagen agreement and beyond

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    Also in the global South, transport already significantly contributes to climate change and has high growth rates. Further rapid motorisation of countries in Asia and Latin America could counteract any climate efforts and aggravate problems of noxious emissions, noise and congestion. This Paper aims at connecting the need for transport actions in developing countries to the international negotiations on a post-2012 climate change agreement. It outlines the decisions to be taken in Copenhagen and the preparations to adequately implement these decisions from 2013. Arguing, that a sustainable transport approach needs to set up comprehensive policy packages, the paper assesses the substance of current climate negotiations against the fit to sustainable transport. It concludes that the transport sector's importance should be highlighted and a significant contribution to mitigation efforts required. Combining the two perspectives lead to several concrete suggestions: Existing elements of the carbon market should be improved (e.g. discounting), but an upscale of the carbon market would not be an appropriate solution. Due to a lack of additionality, offsetting industrialised countries' targets would finally undermine the overall success of the climate agreement. Instead, a mitigation fund should be established under the UNFCCC and financed by industrialised countries. This fund should explicitly enable developing countries to implement national sustainable development transport and mobility policies as well as local projects. While industrialized countries would set up target achievement plans, developing countries should outline low carbon development strategies, including a section on transport policy. -- Die rasante Motorisierung Asiens und Lateinamerikas könnte die Klimaschutzerfolge konterkarieren. Bis 2030, so Prognosen der IEA, werden im Verkehrssektor 2,5 Gigatonnen CO2 mehr emitiert als heute; 80 Prozent davon in den Ländern des Südens. Das Papier soll die Notwendigkeit verdeutlichen, dass in den Entwicklungsländern im Verkehrssektor heute schon Maßnahmen ergriffen werden müssen und die Klimaverhandlungen für die Post-Kyoto-Phase eine wichtige Gelegenheit sind. Die Ansätze in den gegenwärtigen Klimaverhandlungen werden den Anforderungen einer nachhaltigen Verkehrspolitik gegenübergestellt und dafür plädiert, den Stellenwert des Verkehrssektors zu den Klimaschutzanstrengungen zu erhöhen. Dafür werden mehrere konkrete Vorschläge gemacht: So sollten vorhandene Elemente des Emissionshandels verbessert werden, die eigentlich angemessene Lösung sei jedoch ein neues Instrument: Um die Entwicklungsländer in die Lage zu versetzen Maßnahmen in der Verkehrspolitik umzusetzen und Politiken und Projekte vor Ort zu fördern, sollte ein von den Industrieländern finanzierter Klimaschutzfonds unter dem UN-Klimaregime eingerichtet werden. In Strategien für eine kohlenstoffarme Entwicklung sind dabei die Politikinstrumente einer nachhaltigen Verkehrsentwicklung zu integrieren.

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

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    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

    Energy efficiency and integration of urban electrical transport systems: EVS and metro-trains of two real European lines

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    Transport is a main source of pollutants in cities, where air quality is a major concern. New transport technologies, such as electric vehicles, and public transport modalities, such as urban railways, have arisen as solutions to this important problem. One of the main difficulties for the adoption of electric vehicles by consumers is the scarcity of a suitable charging infrastructure. The use of the railway power supplies to charge electric vehicle batteries could facilitate the deployment of charging infrastructure in cities. It would reduce the cost because of the use of an existing installation. Furthermore, electric vehicles can use braking energy from trains that was previously wasted in rheostats. This paper presents the results of a collaboration between research teams from University of Rome Sapienza and Comillas Pontifical University. In this work, two real European cases are studied: an Italian metro line and a Spanish metro line. The energy performance of these metro lines and their capacity to charge electric vehicles have been studied by means of detailed simulation tools. Their results have shown that the use of regenerated energy is 98% for short interval of trains in both cases. However, the use of regenerated energy decreases as the train intervals grow. In a daily operation, an important amount of regenerated energy is wasted in the Italian and Spanish case. Using this energy, a significant number of electric vehicles could be charged every day

    Emergency Management Training and Exercises for Transportation Agency Operations, MTI Report 09-17

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    Training and exercises are an important part of emergency management. Plans are developed based on threat assessment, but they are not useful unless staff members are trained on how to use the plan, and then practice that training. Exercises are also essential for ensuring that the plan is effective, and outcomes from exercises are used to improve the plan. Exercises have been an important part of gauging the preparedness of response organizations since Civil Defense days when full-scale exercises often included the community. Today there are various types of exercises that can be used to evaluate the preparedness of public agencies and communities: seminars, drills, tabletop exercises, functional exercises, facilitated exercises and full-scale exercises. Police and fire agencies have long used drills and full-scale exercises to evaluate the ability of staff to use equipment, protocols and plans. Transit and transportation agencies have seldom been included in these plans, and have little guidance for their participation in the exercises. A research plan was designed to determine whether urban transit systems are holding exercises, and whether they have the training and guidance documents that they need to be successful. The main research question was whether there was a need for a practical handbook to guide the development of transit system exercises

    Does Rail Transit Save Energy or Reduce Greenhouse Gas Emissions?

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    Far from protecting the environment, most rail transit lines use more energy per passenger mile, and many generate more greenhouse gases, than the average passenger automobile. Rail transit provides no guarantee that a city will save energy or meet greenhouse gas targets. While most rail transit uses less energy than buses, rail transit does not operate in a vacuum: transit agencies supplement it with extensive feeder bus operations. Those feeder buses tend to have low ridership, so they have high energy costs and greenhouse gas emissions per passenger mile. The result is that, when new rail transit lines open, the transit systems as a whole can end up consuming more energy, per passenger mile, than they did before. Even where rail transit operations save a little energy, the construction of rail transit lines consumes huge amounts of energy and emits large volumes of greenhouse gases. In most cases, many decades of energy savings would be needed to repay the energy cost of construction. Rail transit attempts to improve the environment by changing people's behavior so that they drive less. Such behavioral efforts have been far less successful than technical solutions to toxic air pollution and other environmental problems associated with automobiles. Similarly, technical alternatives to rail transit can do far more to reduce energy use and CO2 outputs than rail transit, at a far lower cost. Such alternatives include the following: Powering buses with hybrid-electric motors, biofuels, and -- where it comes from nonfossil fuel sources -- electricity;Concentrating bus service on heavily used routes and using smaller buses during offpeak periods and in areas with low demand for transit service;Building new roads, using variable toll systems, and coordinating traffic signals to relieve the highway congestion that wastes nearly 3 billion gallons of fuel each year;Encouraging people to purchase more fuel-efficient cars. Getting 1 percent of commuters to switch to hybrid-electric cars will cost less and do more to save energy than getting 1 percent to switch to public transit. If oil is truly scarce, rising prices will lead people to buy more fuel-efficient cars. But states and locales that want to save even more energy and reduce greenhouse gas emissions will find the above alternatives far superior to rail transit
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