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The impacts of the already decided increase in rail infrastructure charges in Sweden are described for various market segments within the rail transport system and on the aggregate level for society as a whole. The need for complementary measures in the road transport system is also discussed. Likewise, the paper also mentions the impact of increased rail infrastructure charges on certain significant industrial sectors. An increase in rail charges may reduce social welfare even though the reduction in rail transport mileage is small. This is mainly due to large non-internalised absolute externalities for road freight. For commuter trains, the infrastructure charges' share of the costs of rail transport is expected to rise to 13 percent, which in an international perspective still will be small. 相似文献
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We construct a first country-wide model of demand for road use and of road safety outcomes for Algeria making use of the DRAG-type framework and of flexible regression estimation methods that make a demonstrable difference to the quality of our results. We imply that the availability of high quality Algerian data could make it worthwhile not only to consider updates of the model with longer data series but also to study variants of the model, notably with disaggregation of freight activities across industrial sectors. 相似文献
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This paper reviews road safety performance in the United States. The paper develops a framework for assessing dimensions of road safety, and analyzes the importance of economic factors, travel patterns, demographics, road/traffic/vehicle technology, driver behavior, and public policy. Issues and challenges for future road safety research are discussed. 相似文献
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An extensive body of theoretical and empirical work has been undertaken in the UK since the middle of the last century on the estimation of values of safety for use in the appraisal of proposed transport projects, particularly road and rail. This research has focused largely on ‘willingness-to-pay’ based values in order to measure the strength of the travelling public's preference for marginal improvements in transport safety, relative to consumption of other goods and services. In terms of practical policy making, the research has resulted in a set of values for the prevention of statistical fatalities and non-fatal injuries that are applied not only in transport safety decision making, but also in other public sector contexts. This paper summarises the main findings of this research. 相似文献
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在Logit动态的基础上建立了收费和通行能力的联合控制模型,通过控制时变的道路收费水平和通行能力,优化交通流的演化轨迹,使交通系统达到最优。通过简单的算例,在Logit动态的基础上对道路中的交通流进行分析和预测,进而对车辆进行诱导,从而达到交通管理的目的。 相似文献
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This first part of the state-of-the art focuses on the origins of road safety modeling, covering data, early models and the public health context of model formulation and use. 相似文献
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The third part of the state-of-the-art focuses on the future of road safety modeling and on conjectures concerning the evolution of national safety indicators. In the absence of econometric developments specific to road safety modeling, the research future must rely on pre-existing statistical procedures of econometrics applied to discrete/count and to aggregate data. In terms of contents, growing interest in the heterogeneity of road accident outcomes by category of victims could lead to treatments of this issue across research streams, say by top-down and bottom-up developments, but this speculation does not rest on extant adequate formulations of the issue of road user class and victim analysis. But understanding the time profile of aggregate national performance indicators is quite another matter. 相似文献
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Rationality is an ideal for transport safety policy. As developed within normative welfare economics, rationality denotes the efficient use of safety measures based on cost–benefit analyses that include all relevant impacts of the measures. Efficiency in the technical sense of the term provides a perfectly clear and precise guideline for policy priorities. Nevertheless, some choices that are guided by cost–benefit analysis may strike us as paradoxical or counterintuitive. A paradox of rationality refers to any situation in which conflicting choices can both be defended as rational. This paper discusses a number of choices that may seem paradoxical. The first involves the choice between options that have identical impacts on safety, but in which these impacts are valued differently. The second deals with the tendency for preference reversals to occur when preferences for the provision of safety are aggregated. The third discusses the inability of conventional measures of willingness-to-pay to reflect the intensity of preferences. The fourth concerns the tendency for policy choice to favour the rich at the expense of the poor when willingness-to-pay is not adjusted for the marginal utility of money. A fifth situation refers to the fact that a policy option that looks attractive ex ante may fail an ex post compensation test because utility functions depend on health state. There is a potential conflict between individual and collective rationality with respect to the costs and benefits of some road safety measures. When developing a road safety programme, a set of road safety measures whose benefits exceed the costs when considered as stand-alone measures could have benefits smaller than cost when combined in a programme consisting of all the measures. Finally, there is a potential conflict between efficiency and negotiated consensus as mechanisms of resource allocation in the public sector. The sources of the paradoxes and ways of avoiding them are discussed. Some of the paradoxes can be avoided if changes in risk are valued in terms of a fixed price per unit of risk rather than according to a non-linear demand function. 相似文献
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Martha Grabowski Premnath Ayyalasomayajula Jason Merrick Denise Mccafferty 《Maritime Policy and Management》2013,40(5):405-425
Leading indicators, one type of accident precursor, are conditions, events or measures that precede an undesirable event and that have some value in predicting the arrival of the event, whether it is an accident, incident, near miss, or undesirable safety state. Leading indicators are associated with proactive activities that identify hazards and assess, eliminate, minimize and control risk. An empirical analysis of leading indicators of safety for an international energy transportation company was undertaken, utilizing a previously validated research model. Quantitative safety performance and qualitative safety culture data were obtained from 943 participants on 37 vessels from three fleets in the organization. Organizational, vessel and individual safety factors and leading indicators were identified and an analysis of fleet, vessel, and individual safety cultures was undertaken. The results indicate that individual and vessel-level leading indicators can provide important input to an organization's continuous safety measuring and monitoring systems. 相似文献
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Martha Grabowski Premnath Ayyalasomayajula Jason Merrick Denise Mccafferty 《Maritime Policy and Management》2007,34(5):405-425
Leading indicators, one type of accident precursor, are conditions, events or measures that precede an undesirable event and that have some value in predicting the arrival of the event, whether it is an accident, incident, near miss, or undesirable safety state. Leading indicators are associated with proactive activities that identify hazards and assess, eliminate, minimize and control risk. An empirical analysis of leading indicators of safety for an international energy transportation company was undertaken, utilizing a previously validated research model. Quantitative safety performance and qualitative safety culture data were obtained from 943 participants on 37 vessels from three fleets in the organization. Organizational, vessel and individual safety factors and leading indicators were identified and an analysis of fleet, vessel, and individual safety cultures was undertaken. The results indicate that individual and vessel-level leading indicators can provide important input to an organization's continuous safety measuring and monitoring systems. 相似文献
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道路交通事故应急救援体系能最大限度地降低交通事故的人员伤亡和财产损失,快速恢复正常的交通通行能力。本文研究并建立了城市道路交通应急救援体系,提供了城市道路交通安全软科学方面的支持。 相似文献
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Road safety policies and automobile insurance contracts often use incentive mechanisms based on traffic violations and accidents to promote safe driving. Can these mechanisms improve road safety efficiently? Do they reduce asymmetric information between drivers and insurers and regulators? In other words, is there residual asymmetric information in observed distributions of accidents and infractions? We answer these questions in this article by reviewing recent theoretical and empirical results that rest on various data and methodologies. We present recent tests related to the identification of residual asymmetric information in road safety management and in automobile insurance contracting. We also propose a theoretical analysis of the foundations of point-record driver's licenses observed around the world. 相似文献
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分析了在山区公路水运工程施工中推行机械设备租赁的必要性与可行性,列举了当前山区公路水运工程施工机械设备租赁存在的问题,探讨了完善山区公路水运工程施工机械租赁市场的相关措施。 相似文献
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精确评估模块柔性连接性能对连接器和超大型浮体的结构安全性具有重要意义,而模型试验是获取超大型浮体模块柔性连接性能的必要手段。文章以横向浮筒式的浅吃水超大型浮体为研究对象,根据连接器动响应计算结果,设计了柔性连接器模型;通过不同幅值和载荷组合的连接器静态拉伸和压缩试验,研究了超大型浮体连接器的刚度特性,探讨了组合载荷对连接器刚度的影响;通过不同幅值和周期的连接器纵向动态载荷试验,研究了超大型浮体连接器在动态载荷作用下的结构响应,验证了超大型浮体连接器结构的安全性和适用性。试验结果表明在静态和动态载荷作用下文中设计的柔性连接器连接可靠、结构安全,连接器载荷、位移和应力测量结果可为验证连接器结构设计和计算方法提供依据。 相似文献
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在沥青路面的施工后,我们经常会看到在已完成的沥青路面上有一道道比较明显的直线,这些直线主要是由于沥青混合料离析产生的;离析的产生使得这一部分路面在投入使用后由于雨水的浸入,早早的产生水损害。本文将对施工过程中沥青混合料离析现象的成因进行分析,并提出一些可行的解决方法和措施。 相似文献
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王新彦 《江苏科技大学学报(社会科学版)》2009,23(6):509-511
针对越野赛车车架的强度和刚度的合理匹配问题,利用ANSYS软件建立了美国某Mini-Baja越野赛车前碰撞的有限元模型,模拟该车在乡村路面上以48km/h的速度撞树的情况,得到了碰撞过程中前横梁的位移、速度随时间变化曲线及整车应力分布图.模拟结果表明:该车车架材料的强度和刚度达到了美国FMVSS203安全法规的要求;采用有限元软件ANSYS对小型越野赛车进行碰撞分析,为材料强度和刚度的选择提供了有效的手段. 相似文献