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51.
Loss and damage caused by unscheduled events, especially earthquakes, have sudden and significant impacts not only on the region’s economy where the event occurs but also on other regions. The New Madrid Seismic Zone, located in the center of the United States, could have great impacts on economic activities related to this area, if a major earthquake occurred. Based on the 1993 US Commodity Flow Survey [US Commodity Flow Survey, 1993. Available from: <http://www.bts.gov/ntda/cfs/prod.html>], more than 42% of total commodity flows in the US are related to the greater Midwest, which includes the New Madrid Seismic Zone. If a catastrophic earthquake occurred in this area, the indirect damages could spread far beyond the region, and could have sizable impacts on other regions. A model of interregional commodity flows, incorporating regional input–output relationships, and the corresponding transportation network flows, was applied to assess the economic impacts of such an unexpected event. The economic impacts from the event are described for three hypothetical scenarios, analyzing the magnitude and the extent of the direct and indirect impacts. These analytical results may be used to propose strategic management of the recovery and reconstruction efforts after the event.  相似文献   
52.
A conceptual analysis of the transportation impacts of B2C e-commerce   总被引:4,自引:1,他引:4  
This paper discusses, at a conceptual level, a number of issues related to the evaluation of the transportation and spatial impacts of e-shopping. We review the comparative advantages of store shopping and e-shopping, and conclude that neither type uniformly dominates the other. We identify the building blocks of the shopping process, and note that information and communications technologies are making possible the spatial and temporal fragmentation and recombination of those elements. We analyze future shopping-related changes in transportation as the net outcome of four different fundamental causes, that can be viewed hierarchically: (1) changes in shopping mode share (i.e. shifts in the proportion of shopping activities conducted through store shopping, e-shopping and other modes), keeping the volume of goods purchased and per capita consumption spending constant; (2) changes in the volume of goods purchased, keeping per capita consumption spending constant; (3) changes in per capita consumption spending, independent of demographic changes; and (4) demographic changes. Some factors result in reduced travel while others lead to increased travel. The combined outcome of all factors does not appear to support any hope that e-shopping will reduce travel on net; to the contrary there may be negative impacts due to increased travel, even if those impacts are likely to be localized and/or small in magnitude for the most part. Thus, on the whole, we are likely (with some exceptions) to see continued adoption of both store shopping and e-shopping. Consumers will blend both forms as they conduct a sequence of shopping activities, and retailers will blend both in marketing to and serving customers. Assessing the transportation impacts of e-shopping – even in the short term, let alone the long term – presents some formidable measurement challenges. Nevertheless, those challenges are worthy of our most creative efforts at solution.  相似文献   
53.
Improvements in geographical information systems, the wider availability of high-resolution digital data and more sophisticated econometric techniques have all contributed to increasing academic interest and activity in long-term impacts of transport infrastructure networks (TINs) on land use (LU). This paper provides a systematic review of recent empirical evidence from the USA, Europe and East Asia, classified regarding the type of transport infrastructure (road or rail), LU indicator (land cover, population or employment density, development type) and outcome (significance, relationship’s direction) as well as influential exogenous factors. Proximity to the rail network is generally associated with population growth (particularly soon after the development of railway infrastructure), conversion to residential uses and the development of higher residential densities. Meanwhile, proximity to the road network is frequently associated with increases in employment densities as well as the conversion of land to a variety of urban uses including commercial and industrial development. Compared with road infrastructure, the impact of rail infrastructure is often less significant for land cover or population and employment density change. The extent of TINs’ impact on LU over time can be explained by the saturation in TIN-related accessibility and LU development.  相似文献   
54.
Environmental nuisances (such as greenhouse gases and noise) may be generated during the use phase of the pavement life cycle, with these known to significantly affect the environment. However, no attempt has yet been made to gather information concerning the processes involved in the generation of environmental impacts, and to evaluate them. To address this issue, this paper reviews the knowledge base and relevant methods relating to environmental impact assessment and pavement management. It then presents a conceptual model, integrating impact pathway approach and life cycle cost analysis principles and providing a comprehensive framework for quantification and incorporation of environmental impacts into pavement management. This study shows that pavement management influences environmental impacts occurring during the use phase of the pavement life cycle. It establishes causal links between pavement management and nuisance generation, between nuisances and their impact on receptors, and finally between these impacts and their costs. This study also suggests that incorporating environmental impacts into pavement management systems is feasible and describes how existing and future methodologies and tools may be integrated to support this incorporation. Finally, this study underlines that the inaccuracy of current knowledge and data limits the scope of this conceptual model to network-level decisions.  相似文献   
55.
注重铁路安全监督和安全信息的综合利用,是国际上通行的一种做法.伴随着我国铁路事业的发展,铁路安全信息的重要性得以凸显出来.为充分发挥安全信息在安全生产中的实效、快捷、准确的处理和传输功能,正确分析安全生产形势,准确实施决策,建立一套"铁路安全信息综合管理系统",在实际工作中取得很好的效果.  相似文献   
56.
Road transport imposes negative externalities on society. These externalities include environmental and road damage, accidents, congestion, and oil dependence. The cost of these externalities to society is in general not reflected in the current market prices in the road transport sector.An efficient mobility model for the future must take into account the true costs of transport and its regulatory framework will need to create incentives for people to make sustainable transport choices. This paper discusses the use of economic instruments to correct road transport externalities, but gives relatively more weight to the problem of carbon emissions from road transport, as this is particularly challenging, given its global and long-term nature.Economics offers two types of instruments for addressing the problem of transport externalities: command-and-control and incentive-based policies.Command-and-control policies are government regulations which force consumers and producers to change their behaviour. They are the most widely used policy instruments. Examples include vehicle emission and fuel standards in the US as well as driving or parking restrictions in Singapore. The implementation cost of these instruments to the government is small. Although from an economic perspective these policies often fail to achieve an efficient market outcome, the presence of political constraints often make them the preferred option, in terms of feasibility and effectiveness.Economic theory shows how policies, which affect consumption and production incentives, can be used to achieve the optimal outcome in the presence of externalities. Incentive-based policies function within a new or an altered market. We first examine incentive-based policies, which cap the aggregate amount of the externality, such as carbon emissions, by allocating permits or rights to the emitters. The emitters are then free to trade their permits amongst them. The permit allocation mechanism is important-although market efficiency would be satisfied by an auction, political influences usually favour a proportional allocation based on historic emissions. We discuss EU ETS as an example of a cap-and-trade system, however, no such policy for CO2 emissions in road transport has been implemented anywhere in the world to date.Fiscal instruments are, like command-and-control, widely used in road transport, because they are relatively cheap and simple to implement. They include the use of taxes and charges in order to bridge the gap between private and the social costs and, in principle, can lead to an efficient market solution. Registration, ownership, fuel, emissions, usage taxes, and parking and congestion charges have been implemented in many countries around the world. On the other side of the spectrum, subsidies can be given to those scrapping old cars and buying fuel-efficient vehicles. Some cities, such as London, have implemented congestion charges and many states in the United States have introduced high occupancy lanes. Other interesting possibilities include pay-as-you-drive insurance and other usage charges. However, the size and scope of taxes and subsidies are determined by governments, and because of their imperfect knowledge of the market the outcome is still likely to be inefficient.Governments have many effective economic instruments to create a sustainable road transport model. These instruments can be used separately or together, but their implementation will be necessary in the nearest future.  相似文献   
57.
Various fields and commercial sectors have witnessed a transformation with the advent of the internet. In the last decade, the retail sector in particular has witnessed the massive growth of e-commerce. This has also significantly altered our shopping experiences, influencing a range of decisions, from where, how, and how much to shop. With the consistent growth of e-commerce transactions, more trucks than ever before are entering cities today, bringing with them the negative externalities of increased congestion and pollution. This study first unravels underlying shopping behaviors–both in-store and online–using the 2016 American Time Use Survey (ATUS) data. The authors also develop an econometric behavioral model to understand the factors that affect shopping decisions. At a macro level, the disaggregate individual shopping behaviors are studied by implementing the model to synthetic populations to estimate potential vehicle miles traveled and environmental emissions in two metropolitan areas, Dallas and San Francisco (SF). Finally, the study estimates the impacts of rush deliveries, basket size, and consolidation levels by developing a breakeven analysis between in-store and online shopping. These results confirm the importance of managing the urban freight system, including delivery services and operations, to foster a more sustainable urban environment.  相似文献   
58.
Electrification is widely considered as a viable strategy for reducing the oil dependency and environmental impacts of road transportation. In pursuit of this strategy, most attention has been paid to electric cars. However, substantial, yet untapped, potentials could be realized in urban areas through the large-scale introduction of electric two-wheelers. Here, we review the environmental, economic, and social performance of electric two-wheelers, demonstrating that these are generally more energy efficient and less polluting than conventionally-powered motor vehicles. Electric two-wheelers tend to decrease exposure to pollution as their environmental impacts largely result from vehicle production and electricity generation outside of urban areas. Our analysis suggests that the price of e-bikes has been decreasing at a learning rate of 8%. Despite price differentials of 5000 ± 1800 EUR2012 kW h−1 in Europe, e-bikes are penetrating the market because they appear to offer an apparent additional use value relative to bicycles. Mid-size and large electric two-wheelers do not offer such an additional use value compared to their conventional counterparts and constitute niche products at price differentials of 700 ± 360 EUR2012 kW−1 and 160 ± 90 EUR2012 kW−1, respectively. The large-scale adoption of electric two-wheelers can reduce traffic noise and road congestion but may necessitate adaptations of urban infrastructure and safety regulations. A case-specific assessment as part of an integrated urban mobility planning that accounts, e.g., for the local electricity mix, infrastructure characteristics, and mode-shift behavior, should be conducted before drawing conclusions about the sustainability impacts of electric two-wheelers.  相似文献   
59.
This paper presents a GIS-based multi-objective optimization model, particularly designed to aid highway engineers and planners in proposing competitive highway alignment alternatives when building a new highway or expanding an existing highway. The proposed model can effectively examine tradeoffs among various objectives that represent possibly conflicting interests of different stakeholders. A Hybrid Multi-Objective Genetic Algorithm, which utilizes designers’ knowledge about the preference of decision makers, is developed to search for a set of Pareto-optimal solutions with an acceptable level of diversity. Two case studies demonstrate the capability of the proposed approach in providing multiple trade-off solutions. The results indicate that the incorporation of preference information, even if preliminary in nature, has great potential to save computation time and improve the quality of the obtained Pareto-optimal set.  相似文献   
60.
Utilizing daily ridership data, literature has shown that adverse weather conditions have a negative impact on transit ridership and in turn, result in revenue loss for the transit agencies. This paper extends this discussion by using more detailed hourly ridership data to model the weather effects. For this purpose, the daily and hourly subway ridership from New York City Transit for the years 2010–2011 is utilized. The paper compares the weather impacts on ridership based on day of week and time of day combinations and further demonstrates that the weather’s impact on transit ridership varies based on the time period and location. The separation of ridership models based on time of day provides a deeper understanding of the relationship between trip purpose and weather for transit riders. The paper investigates the role of station characteristics such as weather protection, accessibility, proximity and the connecting bus services by developing models based on station types. The findings indicate substantial differences in the extent to which the daily and hourly models and the individual weather elements are able to explain the ridership variability and travel behavior of transit riders. By utilizing the time of day and station based models, the paper demonstrates the potential sources of weather impact on transit infrastructure, transit service and trip characteristics. The results suggest the development of specific policy measures which can help the transit agencies to mitigate the ridership differences due to adverse weather conditions.  相似文献   
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