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491.
The demand for inland freight transport in Europe is mainly met by road transport, leading to unsustainable impacts such as air pollution, greenhouse gas emissions and congestion. Since rail transport has lower externalities than road transport, a modal shift from road to rail is an accepted policy goal for achieving a more sustainable and competitive transport system. However, intermodal road–rail transport is mainly competitive for long-distance transport, and as a consequence, the potential for modal shift is limited. The cost efficiency of road–rail intermodal transport is particularly sensitive to pre- and post-haulage (PPH) costs, since this activity typically has a larger cost compared with its share of the total distance in the transport chain. For intermodal transportation over shorter distances, for example, below 300 km and where there are substantial PPH activities at both ends of the chain, the competitiveness of the intermodal transport system compared with that of direct road is low. Improving the efficiency of PPH activities is, therefore, of utmost importance for the competitiveness of the intermodal transport system. This paper looks into the issue of improving the cost efficiency of an intermodal transport chain by implementing an innovative and flexible legal framework regarding the PPH activities in the chain. By extending the legal framework with exemptions for longer vehicles in PPH, the cost efficiency could be greatly improved. The purpose of such a framework is to allow and enable, for PPH exclusively, the use of 2?×?40 foot or even two semi-trailers using only one vehicle in the context of the Swedish regulatory framework. This paper develops a strategic calculation model for assessing and investigating the consequences of such a framework and investigates the framework's potential in terms of cost efficiency. The model in combination with a sensitivity analysis of input variables gives a comprehensive understanding of the effects of PPH under different circumstances. From the results, it is evident that there are substantial positive effects associated with a PPH framework of longer vehicles. Results indicate that a typical shipper may experience cost reductions of about 5–10% of the total costs of the intermodal transport chain. In summary, a more innovative and flexible legal framework regarding vehicle length in the PPH links can contribute to a greater modal shift, improved cost efficiency and more environmentally friendly transportation systems.  相似文献   
492.
The aim of this article is to analyze the interaction between port devolution processes in Portugal and Spain in their common geographical environment, the Iberian Peninsula. Firstly a review is done of the different port devolution processes in the world which specifically analyses the transition of numerous public and centralized ports to the landlord model. Among the conclusions that we can highlight with respect to the Iberian port systems are the need for a reflection process before any change is made to the port governance model, and greater cooperation between the two countries to avoid any possible future port tariff price wars. The over-investment process that the Spanish port devolution process, especially, has generated must also be mentioned, for highlighting once again the almost inexhaustible ability of ports to eat up public funds for investment that precludes profitability.  相似文献   
493.
Abstract

Each year more than 1000 pedestrians are injured in accidents on pedestrian crossings in Switzerland. The accidents often occur in darkness, twilight or poor visibility during rain at locations without sufficient public street lighting because vehicle drivers notice the pedestrian crossing too late or overlook it altogether. Pedestrian crossings can be made significantly easier for vehicle drivers to recognize at night and in poor visibility by means of HMB reflectors. When crossing sites are made more conspicuous with high horizontal retro‐reflecting markers, the readiness to stop increases. The reflectors can thus contribute to improving road safety at pedestrian crossings. This new low‐cost measure has a wide range of applications. The new reflector system is currently gaining ground in Switzerland and several other European countries.  相似文献   
494.
The feasibility of implementing short sea shipping (SSS) between two specific ports has been typically approached on the operative level, in terms of time and cost for a specific origin–destination pair. This paper focuses on the strategic level. Particularly, its goal is to study the potential of SSS in different industrial sectors by analysing their freight-distribution strategies. To achieve the objective, some standard freight-distribution strategies are defined based on the requirements of the industry, the demand and the product being transported. The information is complemented with a survey of more than 100 Spanish companies distributing internationally. As a result it is concluded that there are economies of scale related to the size of the carrier (the ship) and its capacity to absorb the variability in demand. This potential increases with the cargo value. Additionally, a framework of supply/distribution chains is provided which can help to identify potential customers/sectors and the feasibility of new potential shipping lines. The value of this paper resides in its approach (strategic, instead of operational/tactical), and the solid groundwork point provided for future researchers.  相似文献   
495.
Abstract

Fisheries management in the USA, as governed by the Magnuson–Stevens Fishery Conservation and Management Act (MSA), has been decidedly more successful at meeting its conservation goals than has fisheries management in the EU, as governed by the Common Fisheries Policy (CFP). In an effort to explain the different outcomes in these two systems that share many management attributes, we evaluated them against a list of effective governance attributes gleaned from the literature. We also examined the distribution of rights and responsibilities within each system, and the resulting stewardship incentives. Five effective governance attributes are fully realized under the MSA but have historically been absent from the CFP system: adequate regulatory authority, effective enforcement mechanisms, science-based decision-making, conservation-oriented goals and clear objectives, and directives. These governance system gaps, along with uneven distributions of rights, responsibilities, and incentives, may be responsible for the observed difference in conservation outcomes.  相似文献   
496.
Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD).

An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip.

It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links.  相似文献   
497.
Aluminum alloys are important technological materials for the application on lightweight design and development of vehicle body. The research works for characterizing warm forming behavior of aluminum alloys have generally reported. However, there were few researches focused on the flow behavior of warm forming aluminum alloy parts for the energy absorbing performance during crash. The tensile stress-strain response for warm forming AA5182 specimens tested under the strain rates of 0.0015 s?1, 0.015 s?1, 0.15 s?1 and 1.5 s?1 are presented in this paper. The data were fit to the Johnson-Cook constitutive model for the simulation of frontal impact. The energy absorbing performance of warm forming AA5182 parts were analyzed. The results show the higher flow stresses and lower fractured strain of warm forming aluminum alloy parts with the strain rate increasing. The flow stresses of warm forming aluminum alloy parts are insensitive to strain rate, while the fractured strain and elongation are sensitive to strain rate. The intrusion displacement of the warm forming aluminum alloy parts is appropriate for the satisfaction of vehicle body design avoiding the excessive deformation for the injury of passenger or the failure of frontal door opening. The feasibility of warm forming aluminum alloy parts is verified with the analysis of energy absorbing performance, stiffness and modal of vehicle body.  相似文献   
498.
The use of a regenerative braking mode can reduce overall vehicle energy usage for most of the most common drive cycles. However, a number of technical issues restrict the use of regenerative braking for all possible braking situations. These issues are concerned with two key limitations. The first is related to physical limitations of the applied regenerative braking system, e.g. Electric Motor (E-Motor) power limits; energy storage device capacity and vehicle load transfer etc. The second limitation results from the potentially detrimental interaction between regenerative braking and the Anti-locking Braking System (ABS). The first type of limitation can, to some extent, be alleviated by suitable choice of hardware and, as a consequence, will not be discussed further in this paper. The second type of limitation concerns the regenerative braking strategies during an ABS event. Some of the regenerative braking strategies designed and investigated within the Low Carbon Vehicle Technology Project (LCVTP) will be described and analyzed in this paper. A comparison of competing strategies is made and conclusions are drawn together with suggestions for further research. The work has been progressed as a part of a major research programme; namely the LCVTP, which has been conducted within an extensive industrial and academic partnership, mutually funded by the European Regional Development Found and Advantage West Midlands.  相似文献   
499.
Pooling, or ride-sharing, is a term coined in the United States (U.S.) to describe various forms of collective travel organised for, and often by, specific groups of commuters with similar travel requirements. Its different forms include bus pooling (financially self-supporting works bus or commuter coach services), minibus pooling (van pooling in U.S. terminology) and car pooling. It has been claimed that these forms of collective travel offer a more personalised service than conventional stage carriage buses, and therefore have a greater chance of attracting solo car drivers and increasing vehicle occupancies. This, in turn, can lead to lower fuel consumption and reduced traffic congestion at peak times. Following the advent of oil shortages in the winter of 1973/74, considerable efforts were made in the U.S. to promote pooling initiatives. This gave rise to the publication of a substantial volume of literature that sometimes indicated significant resource-saving achievements. This paper considers the potential for bus, minibus and car pooling in Great Britain, drawing both on relevant theoretical and economic studies, and on practical operational experience. It concludes that under reasonable assumptions about the transport situation in the next decade or so, pooling could become increasingly useful for solving the travel problems of individual local groups, but that it is unlikely to become a major mode in terms of the numbers of trips carried. The effects of recent legislative changes are discussed, and the justification for further change assessed. Relevant comparisons are made with the U.S.Crown Copyright 1983. Extracts from the text may be reproduced, except for commercial purposes, provided the source is acknowledged.  相似文献   
500.
The basis for design of stiffened plates under longitudinal compression is outlined and predictions using several codes are compared against numerical results from an inelastic beam-column formulation and test results. In order to explore the inherent differences in column behaviour separately from discrepancies arising due to plate panel behaviour, the code predictions are re-evaluated adopting a common plate panel effective width formulation. On this basis, a critical review of code methods is made and some modifications are proposed.

The effect of the magnitude and direction of applied uniform bending on the axial capacity of stiffened plates is investigated by comparing two alternative design approaches, namely an interaction equation and a method based on the Perry equation, against results from numerical analyses and from rigid plastic theory. The interaction equation is invariably more conservative than the Perry approach but its simplicity tends to be convenient for routine design applications. Finally, results of numerical analyses, together with experimental results from previous studies, on continuous stiffened plates under combined axial compression and lateral pressure are presented and available design guidance is discussed.  相似文献   

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