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101.
The great majority of analyses made in transport economics use, explicitly or, more often, implicitly, the common assumption of perfect competition. This is the case, for instance, when infrastructure projects are evaluated using the mere sum of the surpluses of transport users and providers. Even when putting aside the question of externalities such as noise, safety or environmental quality, the real chain of economic interactions that takes place in transport provision or downstream of transport provision is not taken into account. Surely enough, describing and simulating this chain could be quite complex. Nevertheless, it is not uninteresting to try to estimate if it does make a big difference or not to make this approximation. The paper makes such an attempt for two broad kinds of applications of transport economics: 相似文献
102.
This study uses EUROCONTROL data on operating performance of the national air navigation service providers over the 2002–2011 time period to document in detail the efficiency changes across providers and time using data envelopment analysis. Our results suggest that overall providers’ productivity improved over the time period covered by the data, driven by improvements in technical rather than allocative efficiency. However, some trend reversals in the post-2008 crisis period are also observed. 相似文献
103.
Do reforms reduce the magnitudes of cost overruns in road projects? Statistical evidence from Norway
Although governments often respond to the prevalent cost overruns of transportation projects by reforming the agencies charged with overseeing the construction of projects, the transportation research literature has not provided statistical evidence as to whether such reforms assist in reducing cost overruns. This paper provides such evidence using the Norwegian road sector as a case study. The agency in question was reformed twice, from a monopolistic to a semi-monopolistic organization, and finally, to a fully competitive organization in which road construction was divided out into a separate company and privatized. In this work, we use statistical inferences to explore the related issues. The data set is composed of 1045 projects evenly distributed across the three organizational forms. The results demonstrate that the impact of the reforms has not been equal. The most important impact occurred in the final reform of full competition in which both the cost overruns and delays in construction among larger projects were greatly reduced. The second reform appears to have had a contrasting impact. For transportation research in general, we call for additional studies that will reveal the extent to which efforts carried out by governments (such as reforms) improve the efficiency of these sectors. 相似文献
104.
建设管理阶段的成本控制,是项目建设管理的重要环节。文章以六寨至河池高速公路№5合同段建设管理工作为例,强调了成本控制在项目建设管理工程中的重要性,分析了影响高速公路工程建设成本和进度的常见问题,探讨了在高速公路建设过程中成本控制的方法及措施。 相似文献
105.
106.
沈丹桂 《铁路工程造价管理》2013,28(5):33-35,38
2007年以前修建的水泥混凝土道路,经多年运营,其路面质量明显下降,部分已遭到损坏,已满足不了日益增长的交通流量的需要,需改造成性能优良的黑色沥青路面。此文在阐述道路"白改黑"工程特点的前提下,论述影响道路"白改黑"工程造价的主要因素。并结合工程实例,对可采取的改造方案进行比较,对有关工程造价及指标进行分析,提出推荐方案。 相似文献
107.
张文才 《铁路工程造价管理》2010,25(6):25-28,31
斜拉桥转体施工主要是针对特殊区域、当采用一般施工方法无法实现时而采用的一种施工方法。此文介绍了转体斜拉桥转体体系的工作原理、施工组织、施工方法和控制措施,分析确定了转体体系的施工定额,以期为同类工程提供工程造价的参考依据。 相似文献
108.
胡丽华 《武汉船舶职业技术学院学报》2006,5(5):76-78
通过对各种价格管制模型的分析,揭示其对成本的依赖性,探讨了在价格管制模型的运用中,加强成本管理的重要性。 相似文献
109.
对供应链管理库存控制多级问题进行分析,研究了两种多级库存策略,基于成本优化的多级库存策略,基于时间优化的多级库存策略。两种策略反映了库存管理的一般思想,即库存控制的最优化目标不仅是供应链环节中某一个或几个节点企业的库存最优化,而是整个供应链环节有机、协调地一体化库存的最优化。在此基础上提出了基于时间的多级库存成本优化思路。 相似文献
110.
Mark A. Delucchi Timothy E. Lipman 《Transportation Research Part D: Transport and Environment》2001,6(6)
Regulators, policy analysts, automobile manufacturers, environmental groups, and others are debating the merits of policies regarding the development and use of battery-powered electric vehicles (BPEVs). At the crux of this debate is lifecycle cost: the annualized initial vehicle cost, plus annual operating and maintenance costs, plus battery replacement costs. To address this issue of cost, we have developed a detailed model of the performance, energy use, manufacturing cost, retail cost, and lifecycle cost of electric vehicles and comparable gasoline internal-combustion engine vehicles (ICEVs). This effort is an improvement over most previous studies of electric vehicle costs because instead of assuming important parameter values for such variables as vehicle efficiency and battery cost, we model these values in detail. We find that in order for electric vehicles to be cost-competitive with gasoline ICEVs, batteries must have a lower manufacturing cost, and a longer life, than the best lithium-ion and nickel–metal hydride batteries we modeled. We believe that it is most important to reduce the battery manufacturing cost to $100/kWh or less, attain a cycle life of 1200 or more and a calendar life of 12 years or more, and aim for a specific energy of around 100 Wh/kg. 相似文献