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The planning and implementation of a multimodal transportation system in the Holy City of Makkah to handle the huge volumes of pilgrims to the City is not a straightforward mission, as Makkah poses numerous challenges including its unique seasonal demand patterns, mountainous terrain, and limited space. Aerial ropeway transit (ART), a promising transport technology solution, could be an important component of this system. This paper presents the results of a technical and economic feasibility study to explore the potential of introducing ART service in Makkah. The study reveals that, overall, ART service on some corridors in Makkah is technically feasible, and with some necessary enforcement measures to attract ridership could become a profitable transportation investment. Specifically, the study recommends using ART for special user groups and service/emergency crews during peak seasons and opening ART to the public as a premium service during the off-peak season. 相似文献
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ABSTRACTThis narrative review synthesised the limited work that has been carried out into road safety education targeting parents. Parent education appeared to have a positive impact on child safety seat use and children’s bike helmet use, but results regarding the impact of parent education on pedestrian safety were mixed. The review highlighted important gaps in the literature. A key gap being identifying effective ways to engage parents of low socioeconomic and ethnic minority backgrounds. Further, another gap is understanding effective ways to engage and support parents of children with additional needs to build their children’s road safety skills. There is some evidence that parent education has a positive impact on these “at-risk” groups, but little work on how to engage with these groups and the type of parent education required. 相似文献
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某铁路隧道在下穿冲沟边坡时出现冒顶。针对该隧道工程的实际情况,建立数值分析模型,采用FLAC3D程序模拟隧道施工力学行为,考虑暴雨积水对围岩的影响,从围岩塑性区分布、位移以及锚杆和超前大管棚内力分布情况分析隧道变形和冒顶发生的原因。结果表明:隧道超浅埋、持续降水积水、围岩力学性质差及施工支护不当导致坍方。结合工程实际提出洞内加固、冲沟边坡加固及开挖控制的综合处治方法,取得了理想的效果,为日后类似工程提供借鉴与参考。 相似文献
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Morton E. O’Kelly 《Transportation Research Part D: Transport and Environment》2012,17(7):555-567
Hubs act as switching points for interactions and so are places through which flows are concentrated. This research uses the interactions between a system of cities as an experimental context for understanding selected environmental costs and benefits of concentrated flow. Whether hub based networks create additional environmental costs has been debated in the literature. In this paper, fuel burn is used as an indicator of environmental cost. The essential ideas are: (1) to examine fuel costs associated with larger aircraft; (2) to determine implications of higher loads on dense routes; and (3) to model the resulting implications for hub and gateway location. Variants of these questions apply to passenger and freight flows, and the paper will initially concentrate on passenger models.The paper shows that by modeling fuel burn and introducing a fixed charge (like a set up cost), a multiple allocation hub and spoke model can be adjusted to direct more or less flow onto the inter-facility connector. In other words, usage of multiple connections and direct links can be controlled and modeled as a function of the fixed charge. The resulting networks are characterized by quite different levels of passenger miles, aggregate fuel burn and fixed charges. The preferred network in terms of minimal fuel burn is found by subtracting the fixed set up charge, thereby focusing attention on the modeled fuel burn. The lowest cost set up is a network with a high degree of connectivity, and a pure single assignment hub network has the highest fuel cost (as a result of larger passenger miles needed by connecting paths). The data also allow a tabulation of total passenger miles, which, not surprisingly, track very closely with the fuel burn. In an interesting application of the ideas, it is shown that a fuel efficient network may require a large number of smaller regional jets, and in the interests of avoiding noise and congestion from so many extra airport operations, the carriers may choose to substitute a smaller number of larger planes, thereby slightly increasing fuel needs. This paper also provides a key ingredient for models of an international network where it is impossible to serve many long distance market pairs without consolidation. 相似文献
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为了解决小断面特长隧道施工时经常遇到的以下施工难题:隧道断面小,洞内施工组织难;独头掘进长,洞内通风差;合同工期短,要求进度指标高等,以正在修建的乌兹别克斯坦安革连-琶布铁路隧道安全隧道有轨运输技术应用为例,从有轨运输设备选型、洞内外场地布置、轨线设置和资源配置方面进行了详细介绍,总结出有轨运输方案在小断面特长隧道施工中可实现出碴运输高效、无废气排放利于改善洞内空气质量、解决因断面小施工组织困难等难题。 相似文献