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排序方式: 共有159条查询结果,搜索用时 15 毫秒
31.
Transportation - Sidewalk cyclists are a major concern to planners in many cities around the world: they are considerable in numbers, and increase the risk of injury not only to pedestrians but...  相似文献   
32.
Many decisions taken by mankind are rational only to a limited extent. This holds for individual travel behaviour, but also for long-range strategic decisions on transport systems or transport technology. In any decision problem, coping with uncertainty is the most critical element. The introduction of new transport technology is surrounded by uncertainty. For example, there is uncertainty about the pace and extent of adoption of new technology and there is uncertainty about the impact of new technology in terms of increased sustainability or increased efficiency. This article maps uncertainty surrounding new transport technology and identifies ways in which to deal with uncertainty in policy making. The findings will be illustrated with electric vehicles, particularly with two specific strategies to deal with uncertainty: interactive technology watching and experimentation in a market niche. The paper concludes with a discussion of success factors that influence the outcomes of such strategies.  相似文献   
33.
The effect of motor vehicles upon older neighborhoods has received increasing attention as residents of these areas seek to preserve the quality of life in their neighborhoods. In order to reduce through traffic in residential neighborhoods, numerous techniques have been developed, ranging from turn prohibitions to physical barriers. Since these measures have negative impacts on previous users of the streets, there has been substantial opposition to them. This paper reviews the major areas of conflict as revealed through court challenges.Nine court cases were identified by the researchers. In four, the court decision supported the control measures; in five, the courts decided against the actions. Six of the nine cases are reviewed in this paper. Major legal issues which are identified include the appropriate use of municipal police power, reasonableness in the exercise of police power, the integration of control measures into an overall transportation plan, appropriate consideration of emergency vehicle needs and the rights of access to property, and public participation in the decision. The authors conclude that properly planned and executed diversion strategies can be implemented and can withstand challenges by negatively affected parties.The opinions, findings, and conclusions expressed or implied in this paper are those of the authors only. They are not necessarily those of the Federal Highway Administration.  相似文献   
34.
For a large number of applications conventional methods for estimating an origin destination matrix become too expensive to use. Two models, based on information minimisation and entropy maximisation principles, have been developed by the authors to estimate an O-D matrix from traffic counts. The models assume knowledge of the paths followed by the vehicles over the network. The models then use the traffic counts to estimate the most likely O-D matrix consistent with the link volumes available and any prior information about the trip matrix. Both models can be used to update and improve a previous O-D matrix. An algorithm to find a solution to the model is then described. The models have been tested with artificial data and performed reasonably well. Further research is being carried out to validate the models with real data.  相似文献   
35.
This paper presents the results of a major before-and-after study carried out to establish the short term effects of the removal of a severe bottleneck in the road network around Amsterdam. An important focus in the study was on measuring changes in the timing of travel, as well as changes in route choice, mode choice, destination choice and frequency of travel. The results of the study indicated that, in the short run, there was little or no change in mode choice, nor was there significant emergence of new induced trips. On the other hand, large shifts in time of travel as well as route choice were reported, emphasising the importance of alterations to the timing and routes of existing trips when congestion is relieved, and the need to consider the benefits these bring in evaluating the impact of any road investment.  相似文献   
36.
介绍了北美、欧洲和日本等国家无人驾驶地铁技术的现状及发展情况。  相似文献   
37.
38.
Abstract

Catch share programs are used in fisheries management to meet goals such as species recovery, overcapacity reduction, and economic efficiency. Anticipated impacts include fleet consolidation, infrastructure reduction, and social disruption within communities. The Pacific Coast Groundfish Fishery Social Study (PCGFSS) aims to understand social changes related to the recently implemented West Coast Groundfish Trawl Catch Share Program. In this article, we use a subset of PCGFSS data to explore the ways remaining fishery participants have thus far adapted to catch shares. While some vessels have left the fishery, we found that many participants are adapting to this catch shares program despite challenges. Quota leasing strategies, fishery diversification, gear innovation, and community quota funds are some of the tools participants are using to continue operating under the catch shares program. These early challenges and adaptations to the catch share program are worthy of continued tracking, as researchers, managers, and fishing communities, would benefit by considering first-hand perspectives of the on-the-ground realities of harvesting groundfish in the rationalized fishery.  相似文献   
39.
Sacrificial anodes have become a standard practice for the protection of ballast tanks of merchant vessels against corrosive damage. A well protected tank should extend the life span of a ship and consequently enhances its economic value. An in situ survey comprising more than 100 merchant vessels provided the opportunity to measure the impact of these anodes on the life expectancy of these vessels. Contrary to the general belief of these anodes’ beneficial effect, no significant difference was found in our observations in terms of corrosion occurrence between ship populations with and without sacrificial anodes, across all ship ages. This may be explained by the highly variable conditions and the complex geometry in a ballast tank severely impede optimal and straightforward installation of these anodes in these tanks. Also, poorly placed anodes in it may harm the integrity of the coating of the tank. We therefore plead for uniform and clear rules on anode installation and inspection.  相似文献   
40.
Tom Miller 《中国远洋航务》2006,(11):I0007-I0007
既没有一级城市,也没有超级大港,山东省很少能像广东或江苏那样受到众人瞩目。但是人们却远远低估了山东省的重要性,Tom Miller在青岛为您报道。[编按]  相似文献   
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