981 resultados para Freight cars.


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Two-lane, "microscopic" (vehicle-by-vehicle) simulations of motorway traffic are developed using existing models and validated using measured data from the M25 motorway. An energy consumption model is also built in, which takes the logged trajectories of simulated vehicles as drive-cycles. The simulations are used to investigate the effects on motorway congestion and fuel consumption if "longer and/or heavier vehicles" (LHVs) were to be permitted in the UK. Baseline scenarios are simulated with traffic composed of cars, light goods vehicles and standard heavy goods vehicles (HGVs). A proportion of conventional articulated HGVs is then replaced by a smaller number of LHVs carrying the same total payload mass and volume. Four LHV configurations are investigated: an 18.75 m, 46 t longer semi-trailer (LST); 25.25 m, 50 t and 60 t B-doubles and a 34 m, 82 t A-double. Metrics for congestion, freight fleet energy consumption and car energy consumption are defined for comparing the scenarios. Finally, variation of take-up level and LHV engine power for the LST and A-double are investigated. It is concluded that: (a) LHVs should reduce congestion particularly in dense traffic, however, a low mean proportion of freight traffic on UK roads and low take-up levels will limit this effect to be almost negligible; (b) LHVs can significantly improve the energy efficiency of freight fleets, giving up to a 23% reduction in fleet energy consumption at high take-up levels; (c) the small reduction in congestion caused by LHVs could improve the fuel consumption of other road users by up to 3% in dense traffic, however in free-flowing traffic an opposite effect occurs due to higher vehicle speeds and aerodynamic losses; and (d) underpowered LHVs have potential to generate severe congestion, however current manufacturers' recommendations appear suitable. © 2013 IMechE.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The characteristic of several night imaging and display technologies on cars are introduced. Compared with the current night vision technologies on cars, Range-gated technology can eliminate backscattered light and increase the SNR of system. The theory of range-gated image technology is described. The plan of range-gated system on cars is designed; the divergence angle of laser can be designed to change automatically, this allows overfilling of the camera field of view to effectively attenuate the laser when necessary. Safety range of the driver is calculated according to the theory analysis. Observation distance of the designed system is about 500m which is satisfied with the need of safety driver range.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Transport and its energetic and environmental impacts affect our daily lives. The transport sector is the backbone of the United Kingdom’s economy with 2.3 million people being employed in this sector. With a high dependency on transport for passengers and freight and with the knowledge that oil reserves are rapidly decreasing a solution has to be identified for conserving fuel. Passenger vehicles account for 61% of the transport fuel consumed in the U.K. and should be seen as a key area to tackle. Despite the introduction and development of electric powered cars, the widespread infrastructure that is required is not in place and has attributed to their slow uptake, as well as the fact that the electric car’s performance is not yet comparable with the conventional internal combustion engine. The benefits of the introduction of kinetic energy recovery systems to be used in conjunction with internal combustion engines and designed such that the system could easily be fitted into future passenger vehicles are examined. In this article, a review of automobile kinetic energy recovery system is presented. It has been argued that the ultracapacitor technology offers a sustainable solution. An optimum design for the urban driving cycle experienced in the city of Edinburgh has been introduced. The potential for fuel savings is also presented

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The case for energy policy modelling is strong in Ireland, where stringent EU climate targets are projected to be overshot by 2015. Policy targets aiming to deliver greenhouse gas and renewable energy targets have been made, but it is unclear what savings are to be achieved and from which sectors. Concurrently, the growth of personal mobility has caused an astonishing increase in CO2 emissions from private cars in Ireland, a 37% rise between 2000 and 2008, and while there have been improvements in the efficiency of car technology, there was no decrease in the energy intensity of the car fleet in the same period. This thesis increases the capacity for evidenced-based policymaking in Ireland by developing techno-economic transport energy models and using them to analyse historical trends and to project possible future scenarios. A central focus of this thesis is to understand the effect of the car fleet‘s evolving technical characteristics on energy demand. A car stock model is developed to analyse this question from three angles: Firstly, analysis of car registration and activity data between 2000 and 2008 examines the trends which brought about the surge in energy demand. Secondly, the car stock is modelled into the future and is used to populate a baseline “no new policy” scenario, looking at the impact of recent (2008-2011) policy and purchasing developments on projected energy demand and emissions. Thirdly, a range of technology efficiency, fuel switching and behavioural scenarios are developed up to 2025 in order to indicate the emissions abatement and renewable energy penetration potential from alternative policy packages. In particular, an ambitious car fleet electrification target for Ireland is examined. The car stock model‘s functionality is extended by linking it with other models: LEAP-Ireland, a bottom-up energy demand model for all energy sectors in the country; Irish TIMES, a linear optimisation energy system model; and COPERT, a pollution model. The methodology is also adapted to analyse trends in freight energy demand in a similar way. Finally, this thesis addresses the gap in the representation of travel behaviour in linear energy systems models. A novel methodology is developed and case studies for Ireland and California are presented using the TIMES model. Transport Energy

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study is the first to compare random regret minimisation (RRM) and random utility maximisation (RUM) in freight transport application. This paper aims to compare RRM and RUM in a freight transport scenario involving negative shock in the reference alternative. Based on data from two stated choice experiments conducted among Swiss logistics managers, this study contributes to related literature by exploring for the first time the use of mixed logit models in the most recent version of the RRM approach. We further investigate two paradigm choices by computing elasticities and forecasting choice probability. We find that regret is important in describing the managers’ choices. Regret increases in the shock scenario, supporting the idea that a shift in reference point can cause a shift towards regret minimisation. Differences in elasticities and forecast probability are identified and discussed appropriately.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Each freight forwarder company must independently determine whether factoring is the right choice for them and if will pay off. If the factoring as a financial method would not be economically viable, it certainly would not exist. There are several different financing methods, which are more or less useful. However, not all of them are appropriate for every company, just like all buyers do not represent equal risks for the suppliers. The same buyer can pay one supplier within the agreed period, and not pay the other supplier at all. Still, the most important elements are the agreement made with the customer, the method of insuring ourselves and the method of monitoring the implementation of the agreements. Problems rarely occur overnight and that is why we have to constantly supervise our buyers; otherwise account receivables can occur. My thesis contributes to the ongoing research into how the use of factoring within the Slovenian economic environment can help a small freight forwarder company to grow. In effect, the specific characteristics of the Slovenian economic, legal and institutional environment make such an analysis an interesting one to explore. I used data from a family freight forwarder company TOP Hrvatin in drugi d.n.o. in order to establish future company growth by applying factoring as a right choice of financing. After applying all the data and preparing the company's financial plan, my results suggest that factoring is not the right choice for financing future investments for this particular freight forwarder business. Furthermore, the results even show that factoring is an extremely undeveloped financing method in Slovenia and that practically there is no legal base for its use.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

London’s air quality has improved over recent decades, but is still the worst in the UK. Road transport emissions play an important part in this pollution. A low emission zone (LEZ) would help to accelerate the introduction of cleaner vehicles, and reduce the numbers of older, more polluting vehicles operating in London. The survey work carried out indicates that there is support among goods vehicle operators for an LEZ in London, depending on the precise scheme definition. Operators would generally try to comply with LEZ regulations, with most companies either using technical approaches to ensure that their London vehicle fleet complied with the required emission standard or by redeploying vehicles with the appropriate emission standard from other locations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

London's air quality has improved over recent decades, but is still the worst in the UK. Road transport emissions play an important part in this pollution. A low emission zone (LEZ) would help to accelerate the introduction of cleaner vehicles, and reduce the number of older, more polluting vehicles operating in London. Survey results indicate that there is some support among goods vehicle operators for a LEZ in London, depending on the precise scheme definition. Operators would generally try to comply with LEZ regulations, with most companies either using technical approaches to ensure that their London vehicle fleet complied with the required emission standard, or redeploying vehicles with the appropriate emission standard from other locations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Este trabalho é o relatório de estágio profissional realizado numa companhia francesa de arquitetura, especializado no planeamento urbano, que se-­‐chama AREP. O trabalho desenvolvido teve como objectivo identificar os problemas dos transportes de mercadorias e de logística nas áreas urbanas e da intervenção do planeamento urbano para a mitigação daqueles problemas. Os transportes urbanos de mercadorias são uma prioridade para a definição de políticas num mundo cada vez mais urbanizado. As áreas urbanas necessitam cada vez mais da entrega e recolha de grandes quantidades de mercadorias, resultando na procura de com custos externos elevados e a degradação da qualidade de vida dos residentes. Em 2012, a OECD estimava que as atividades ligadas ao transporte de mercadorias iriam crescer entre 50% e 130% entre 2010 e 2050 nos países da daquela organização. Nos países que não fazem parte da OECD estimava que as atividades iriam crescer entre 250% e 550% durante o mesmo período. Com os problemas já existentes e com o crescimento que está previsto, é importante encontrar soluções que limitem os custos externos e que se encontrem alternativas mais sustentáveis. Tradicionalmente, os formuladores de políticas urbanas tendem a ver os transportes de mercadorias nas áreas urbanas como um problema, em vez de os considerar como um componente essencial do desenvolvimento urbano. Em consequência disso, as políticas implementadas foram desenvolvidas no sentido da restrição na atividade de distribuição de mercadorias. Ao mesmo tempo, os operadores de transporte têm continuado a desenvolver a sua função adequando-­‐se às condições impostas com maiores níveis de eficiência. No entanto, este sucesso tem tido muitos custos externos negativos para a economia, a sociedade e o ambiente. Por isso, os transportes urbanos de mercadorias encontram-­‐se numa tensão constante entre uma logística eficiente e um desenvolvimento urbano sustentável. Hoje, os decisores políticos começam a alterar a perspectiva sobre a intervenção sobre a circulação de transportes de mercadorias, atendendo à sua importância para a economia urbana e, simultaneamente, à necessidade de reduzir os impactes negativos associados ao transporte de mercadorias. Um dos desafios principais é o de compatibilizar as atividades logísticas e os transportes de mercadorias e a preservação das áreas urbanas, minimizando os impactes, garantindo uma boa qualidade de vida para os residentes. Trata-­‐se de um assunto complexo pelos diferentes atores com interesses muitas das vezes conflituantes. A conciliação dos interesses constitui um dos problemas, nomeadamente nas soluções de curto prazo. O espaço disponível para os transportes e as atividades de comércio e serviços emáreas urbanas é limitado. Existe uma grande concorrência sobre o uso do solo urbano entre os diferentes atores.. A necessidade de espaço, conduz a que o sector da logística saía das cidades e se instale nas suas periferias. Esta tendência chama-­‐se ‘logistic sprawl’ e tem vários efeitos negativos, por exemplo, o facto de os veículos terem de percorrer maiores distâncias para os seus clientes nas áreas urbanas. Ao mesmo tempo, os residentes, como consumidores, exigem ter uma grande variedade de produtos disponíveis, esquecendo que para isso há a necessidade de os transportar para e dentro da cidade. Quando as políticas de transportes de passageiros em áreas urbanas se tem vindo a concentrar na alteração modal, do transporte em automóvel para os transportes públicos, ou para a utilização da bicicleta ou a marcha a pé, as políticas de transportes de mercadorias devem igualmente potenciar a utilização de transportes alternativos mais sustentáveis do que o transporte em veículos de mercadorias com motores de combustão interna. Hoje em dia, 75% de todos os transportes de mercadorias por via terrestre a distâncias médias ou longas (mais de 50km), são realizados por via rodoviária. A distâncias mais reduzidas (last mile) essa percentagem é de quase 100%. Estes valores não são compatíveis com um desenvolvimento sustentável. O esforço desenvolvido no sentido da promoção dos modos mais sustentáveis, como a ferrovia e a utilização das vias navegáveis, têm encontrado a oposição das empresas de transporte de mercadorias pois a rodovia é mais flexível (entrega porta-­‐a-­‐porta), com reduzidos custos de utilização de infraestrutura e com custos-­‐fixos mais baixos. Uma cooperação integrada e holística entre os diferentes níveis de governação do território é fundamental, sendo desejável uma maior cooperação entre o sector público e privado. As medidas a implementar têm que ter em conta os problemas a curto e longo prazo. Uma grande variedade de medidas (de regulação, de gestão da infraestrutura, de gestão e ordenamento do território, de promoção e de informação, etc.) têm que ser implementadas e coordenadas em conjunto com o sector privado. As medidas isoladas não resolverão os problemas de transporte de mercadorias na cidade, por isso, o desafio é o de implementar um pacote de medidas diferentes que contribua para uma distribuição das mercadorias mais sustentável, tornando as cidades mais habitáveis. Neste relatório, são discutidas e analisadas as diferentes medidas que podem ser implementadas pelos distintos níveis de governança, incluindo a apresentação de alguns case-­‐studies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The paper compares the approach being taken to freight transport strategy and the specific policy measures being implemented in London and Paris. It highlights the serious consideration that has been given to freight transport by the Mayors of London and Paris in the last five years. These freight policy considerations are taking place against a background of growing levels of road freight activity, energy use and pollutant emissions in both cities. The key freight transport objectives being followed in London and Paris are similar and focus on improving the efficiency and reliability of freight transport while reducing the negative environmental impacts that it causes. The specific freight transport policy measures being followed show some differences in each city. However, attempts to address problems related to loading and unloading are taking place in both, albeit through different specific initiatives. These policy initiatives have important implications for companies concerned with urban logistics operations.