排序方式: 共有93条查询结果,搜索用时 31 毫秒
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Most special-use freeway lanes in the US, whether reserved for carpools, toll-paying commuters or both, are physically separated from the adjacent regular-use lanes by some form of barrier. Vehicle movements in and out of a special lane of this type are permitted only at select access points along the route. The barrier at each select point might open for a distance of 400 m or so. Limiting access in this way is said to reduce the “turbulence” that might otherwise occur were the special lane not to have a barrier, such that vehicles could instead enter or exit that lane anywhere along its length.Yet, real freeway traffic studied in spatiotemporal fashion shows that access points are prone to become bottlenecks. The problem occurs when traffic in the regular lanes becomes dense, as commonly happens during a rush. Drivers then seek refuge in the special lane in greater numbers. Since the vehicular maneuvers through the access point are focused within a limited physical space, they can become disruptive and further degrade traffic. Degradation can occur both in the special lane and in the adjacent regular ones. The damage can be worse than when there is no barrier to limit special-lane ingress and egress.The problem is shown to be reproducible across sites and across days at each site. Policy implications are discussed. Select designs and policies to address the problem are thereafter explored in Part II of the paper using traffic simulation. 相似文献
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Brian Slack 《Research in Transportation Economics》2010,27(1):4-9
This paper investigates the major impacts of the financial tsunami on the maritime industries, notably port and shipping. The maritime industries are still reeling from market declines, with stakeholders still attempting to weather the storm as best as they can through various strategies. However, such strategies are not uniform, where significant diversifications have been noted between major markets and stakeholders. Looking ahead, this paper has identified four major issues, of which they are believed to play key roles in shaping the maritime industries in the post-2008 world. They include the changing patterns of global trades, the importance of being green, the changing government-industrial relations and the need for transparency. Each of these issues has the potential to alter the future maritime industries in diversified, but significant, ways. 相似文献
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Income inequity potentially exists under high occupancy toll (HOT) lanes whereby higher-income travelers may reap the benefits of the facility. An income-based multi-toll pricing approach is proposed for a single HOT lane facility in a network to maximize simultaneously the toll revenue and address the income equity concern, while ensuring a minimum level-of-service on the HOT lanes and that the toll prices do not exceed pre-specified thresholds. The problem is modeled as a bi-level optimization formulation. The upper level model maximizes revenue for the tolling authority subject to pre-specified upper bounds on tolls. The lower level model solves the stochastic user equilibrium problem. An agent-based solution approach is used to determine the toll prices by considering the tolling authority and commuters as agents. Results from numerical experiments indicate that a multi-toll pricing scheme is more equitable and can yield higher revenues compared to a single toll price scheme across travelers. 相似文献
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为了对公交专用进口道设置前后交叉口运行效率做出评价,定量分析其对公交车辆运行的改善效果及对社会车辆的影响,通过分析各种实测饱和车头时距,提出考虑公共汽车形成车队行驶影响的交叉口进口道通行能力大车修正。进一步提出有、无公交专用进口道情况下的社会车辆、公交车辆和车道组的通行能力计算模型,并通过了仿真验证。模型分析表明,公共汽车形成车队行驶会对通行能力产生正面影响,设置公交专用进口道对社会车辆的影响没有预期的严重,当公共汽车在一定比例的情况下可能同时提高公共汽车和社会车辆的通行能力。最后通过实际交叉口案例分析,对结果进行了验证。 相似文献
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苏州市正面临着出行向机动化方式转变的关键时期,公交优先作为缓解城市拥堵的重要策略,是苏州城市可持续发展的重要保障。文章首先分析了优先发展公共交通对苏州的重要意义,阐述了苏州公交发展所面一陆的挑战,接着探讨了如何从规划、政策、服务、管理和具体技术措施如公交专用道的车道位置选择、公交专用道的隔离方式与交通标志设置、公交专用道的停靠站设置形式等几方面保障公交优先发展。文章最后提出了苏州优先发展公共交通的几点建议。 相似文献
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为解决当前公交专用车道设置缺乏评估标准的问题,从个人出行成本和社会成本两个角度出发,对公交专用车道设置前后交通运营成本组成进行分析。在此基础上,重点针对公交专用车道运营的直接效益,通过分析公交专用车道设置前后交通运行参数的变化,分别对运营产出和运营成本进行综合分析,评估公交专用车道设置前后的运能总量、时间及能源消耗成本的变化,并将其折算成货币指标,实现评估指标的定量化。最后,以京通快速路为例进行了评估实证分析。 相似文献
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为了解加利福尼亚州HOV系统的运行效果,基于交通量检测器收集的数据,对HOV系统进行全面分析、评价。最终得到4个主要结论:1)与多条普通车道构成的高速公路相比,包含1条HOV车道的高速公路损失了20%的通行能力;2)HOV车道通常处于两种运行状态,一种是HOV车道未被充分利用,另一种是HOV车道处于超负荷、降级运行状态;3)HOV车道未显著提高小汽车合乘比例;4)在一个相当出色的交通管理系统中,HOV车道并未从整体上缓解道路交通拥堵状况。 相似文献