首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   445篇
  免费   12篇
公路运输   41篇
综合类   171篇
水路运输   44篇
铁路运输   31篇
综合运输   170篇
  2023年   1篇
  2022年   7篇
  2021年   7篇
  2020年   11篇
  2019年   9篇
  2018年   28篇
  2017年   17篇
  2016年   26篇
  2015年   42篇
  2014年   45篇
  2013年   29篇
  2012年   25篇
  2011年   34篇
  2010年   32篇
  2009年   17篇
  2008年   25篇
  2007年   19篇
  2006年   17篇
  2005年   14篇
  2004年   12篇
  2003年   8篇
  2002年   5篇
  2001年   9篇
  2000年   3篇
  1999年   1篇
  1997年   1篇
  1996年   1篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1992年   5篇
  1989年   1篇
  1988年   1篇
排序方式: 共有457条查询结果,搜索用时 896 毫秒
411.
South Africa’s Transnet National Ports Authority’s (TNPA) tariff structure shows imbalances and cross-subsidisation amongst commodities and groups of port users. Benchmarking studies show that South African port costs are below the benchmarked mean for low-value bulk commodities like coal and iron ore, and above the mean for high-value containerised commodities. Vessel charges are also below the benchmarked mean and the required tariff revenues are raised from the tariffs charged to port tenants and cargo owners. This study examines and compares the 2013/2014 TNPA tariff structure with that proposed by the Ports Regulator of South Africa. It compiles, calculates and compares 254 commodity cargo dues with their relevant sector base tariffs for the year. The results indicate the level and direction of cross-subsidisation within and between break-bulk, dry bulk, liquid bulk and containerised cargoes. Of the 254 commodities examined, 100 are below the sector base tariff (being subsidised) and 154 are above (subsidising other cargoes). The findings of this article contribute to the implementation and monitoring of a tariff strategy that will allow for a more reasonable, just and cost reflective TNPA tariff structure.  相似文献   
412.
Artificial markets for mobility credits have been proposed as an alternative to conventional congestion pricing schemes. This paper examines the effects of transaction costs on two types of markets: an auction market and a negotiated market. In an auction market, users purchase all of the needed mobility credits through a competitive bidding process. In a negotiated market, the users initially receive certain amount of mobility credits from the government and trade with each other through negotiation to fulfill their needs. We assume that a brokerage service is built in both markets to facilitate transactions and accordingly, the users have to pay a commission fee proportional to the value of trade. The users are also given the option to purchase credits from the government if for some reasons they cannot use or wish to avoid the markets. Our analyses suggest that the auction market can achieve the desired equilibrium allocation of mobility credits as long as the government sets its price properly and the unit transaction cost is lower than the price that the market would reach in absence of transaction costs. However, in the negotiated market, transaction costs could divert the system from the desired equilibrium regardless of their magnitude. More importantly, the initial allocation of mobility credits may affect the final equilibrium even when marginal transaction costs are constant.  相似文献   
413.
This paper analyzes the climate implications of investments in high speed railway lines given uncertainty in future transport demand, technology and power production. To capture the uncertainty of estimated parameters, distributions for the annual traffic emissions reduction required to compensate for the embedded emissions from the construction of infrastructure are calculated using Monte Carlo simulation. In order to balance the annualized emissions from the railway construction, traffic volumes of more than 10 million annual one-way trips are usually required. Most of the traffic diverted from other modes must come from aviation and the project cannot involve the extensive use of tunnels.  相似文献   
414.
In this paper we report the conclusion of a research project dedicated to pricing regimes in public-private partnership contracts for the provision of transport infrastructure (Macário et al., 2009). Several elements have been brought to the bulk of knowledge that supports the design and implementation of public-private partnership in the transport sector. These developments have been achieved in the following domain:
Understand difficulties of price setting within the PPP environment, given the potential conflict of interest among the different parties engaged, go beyond the discussion of first best versus second-best price setting mechanisms.
Understand the role of government and regulators in the performance of a PPP.
Translate the issue of asymmetries of information between parties into a risk taking language.
Devise alternative contractual designs that will enable competitive price setting.
Understand that a structural element is missing to conciliate the views of the different stakeholders over a PPP: a bridge between infrastructure costs and charges.
The objective of this paper is to overview the main challenges ahead of transport infrastructure pricing, considering the current and likely future policies as well as the field constraints. Moreover, a proposal is formulated to overcome some of the current pitfalls associated to transport infrastructure pricing.  相似文献   
415.
A key attribute of competitive tendering for the periodic selection of operators of subsidised public transport services is to secure the provision of specified services at efficient cost levels. This has proved particularly effective where services were previously provided by an inefficient monopoly operator. The arguments for the adoption of competitive tendering in preference to negotiation with the incumbent operator may be less clear-cut in other cases.Consideration is given to both theoretical and practical insights into the relative merits of competitive tendering and negotiation approaches in such situations. The limited literature on the topic is reviewed and insights and lessons identified. Influencing issues include prior conditions, the nature of the supplier market, features of contracts, negotiating and competitive tendering strategies and practice, accountability and transparency, and long-term market implications. The evidence suggests that ‘one size does not fit all’, and the choice will depend on specific circumstances.The relative merits of the two approaches for renewal of bus contracts are considered with regard to Adelaide, for contracts which have previously been awarded through competitive tendering. The paper draws out the main factors that could influence the authority’s choice between the options, and discusses the relevance of the findings to other situations.  相似文献   
416.
Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.  相似文献   
417.
结合随机通行能力退化路网和双参考点累计前景用户择路模型,构建了引导低碳出行的碳排放收费多准则双层优化模型.上层模型以系统碳排放量最少为目标,搜索最优收费路段并识别最优费率.下层模型基于双参考点累积前景用户和随机退化路网,构建综合考虑行程时间、累积到达时间感知价值、过路费和油费的多准则流量分配模型.设计了基于路段碳密度的启发式算法对模型求解,并采用双向 Nguyen Dupuis路网验证了模型和算法的有效性.研究表明,合理设置收费路段和收费标准能够有效降低全网碳排放总量,但若收费标准设置过高,会降低原瓶颈路段的通行能力,并人为制造新的瓶颈,反而使全网碳排放量上升.  相似文献   
418.
Strand  Jon  Vågnes  Mette 《Transportation》2001,28(2):137-156
We study the relationship between the price of residential property value and proximity to railroads in Oslo, by two different methods, namely a) through a hedonic price study where the statistical relationship between property prices and railroad proximity is estimated, and b) through a multi-attribute utility investigation of real estate agents' evaluation of such a relationship. We find in both cases that there are strong effects of proximity to railroad lines on property prices, at distances less than 100 meters from the lines. In the statistical study log-linear relationships fit the data best, and our estimates indicate that a doubling of the distance from the railroad line, within a 100 meter bound, increases the property price by about 10%. With real estate agents only a linear relationship is probed. This yields an increase in the price of an average relevant housing unit by about 182,000 NOK, due to a increase in the distance to a railroad track from 20 to 100 meters. The equivalent figure from the statistical study is in the range 120–150,000 NOK. The two figures are thus of the same magnitude.  相似文献   
419.
基于车辆动态导航的拥挤定价   总被引:3,自引:0,他引:3  
通过对传统拥挤定价理论局限性的分析,结合车辆动态导航的最新研究成果,提出基于车辆动态导航的拥挤定价新思路,并据此设计出基于车辆动态导航技术的拥挤定价准则。该定价准则能真实地反映交通拥挤在空间上的分布,充分考虑路径之间的相互替代性,及时准确地体现路网交通的动态变化,从而能很好地克服传统理论的弊端。最后分析了基于车辆动态导航拥挤定价的可行性。  相似文献   
420.
为了提高交通信息定价精度,在假定出行者权衡出行时间和出行费用双目标路径诱导的基础上,建立混合均衡定价模型,通过实例对模型进行了标定和验证,对比评价了单目标和双目标路径诱导下的交通信息定价策略,并给出双目标路径诱导下的交通信息定价结果。研究结果表明,与双目标路径诱导相比,单目标路径诱导改变了交通信息定价的可行区域,当具有信息的出行者、交通信息提供者、交通管理者三方各自的利益为决策主体时,交通信息的最终价格分别为1.3、2.6和1.8元,说明了混合均衡定价模型是有效的。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号