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201.
在分析HCM2000 Back of Queue模型计算值偏大的原因中,提出了信号交叉口车辆拖延行为的概念,分析了拖延行为导致Back of Queue模型偏大的2种情况。建立了车辆拖延行为3阶段模型,重点推导了拖延行为模型中,低匀速行驶的时间与不发生拖延行为的正常状况下的停车等待时间之间的关系。根据统计分析,确定低匀速行驶的速度和时间的取值范围,在此基础上推导出车辆发生拖延行为的最大时间间隔Tmax,以及车辆发生拖延行为的条件。讨论了Tmax在考虑拖延行为的排队模型中的应用,是对考虑拖延行为的Back of Queue模型研究的进一步深化。 相似文献
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The primary objective of the study was to evaluate the impacts of an unconventional left-turn treatment called contraflow left-turn lane (CLL) on the operational performance of left-turn movement at signalized intersections. An analytical model was developed for estimating the capacity of left-turn movement at signalized intersections with the CLL design. The capacity model was calibrated and validated using field data collected at six approaches at five signalized intersections in the city of Handan, China. The results of field data analyses showed that the use of CLL design improved the capacity of left-turn movements. However, the capacity gains with the CLL design were quite stochastic considering the randomness in the arrivals of left-turning vehicles. Analytical delay models were proposed for estimating the delay to left-turning vehicles at intersections with the CLL design. A procedure was also proposed for optimizing the location of the upstream median opening and the green interval of the pre-signal. Simulation analyses were conducted to compare the delay experienced by the left-turning and through vehicles at signalized intersections with the conventional left-turn lane, the CLL and another unconventional left-turn treatment entitled “tandem design”. The results showed that both CLL and tandem designs outperformed conventional left-turn lane design; and the CLL design generated less delay to both the left-turning and through vehicles as compared with the tandem design. 相似文献
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近年来,车路协同是汽车与交通行业发展的重要方向之一,而车路协同环境建设和推广也成为先导区建设的重中之重。车路协同系统利用无线通信、传感器检测、高精度地图定位、人工智能、计算机等众多技术来获取车辆和道路信息,在实现人、车、路充分协同的同时,从而达到主动提高道路交通安全、最优化利用系统资源、缓解交通拥挤的目标,形成安全、效率、环保的道路交通系统。先导区一般选址在车流量大、道路环境复杂、附近居住人口密集的区域。先导区内汽车智能与网联化测试、V2X场景实现均需要借助于车路协同系统环境。本文介绍了先导区道路交叉口车路协同系统涵盖的技术,以及实现的功能和信息服务场景,并从车端、路端给出了相应场景的解决方案。 相似文献
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John Jowhell Villegas Wael K.M. Alhajyaseen Hideki Nakamura Azusa Goto 《国际交通安全学会研究报告》2018,42(4):230-239
Signalized intersections are one of the key elements that play a vital role at road networks. The efficiency and safety levels of intersections can affect the operational performance of the whole system. In general, turning traffic, especially median-turning, has always been considered as the most problematic movement in the operation of intersections. This becomes more critical with high turning demand where exclusive turning lanes (single or double) can be assigned to provide larger capacities for these movements and to reduce conflicts with through traffic. However, improper treatment of median-turn lanes could create cross-maneuvering behavior which may limit the expected increase in capacity and create safety issues. Median-turning lane markings are commonly provided at intersections in Japan to guide drivers while turning which is expected to reduce the conflicts among turning traffic. Meanwhile, in the Philippines, exclusive median-turn lanes are installed at intersections without proper treatment which may contribute to the low mobility and safety levels. Therefore, this study evaluated the impact of inside intersection lane markings on the operation of median-turn lanes in terms of mobility and safety. The vehicle maneuver, speed and interactions between the turning traffic were utilized as essential components for the assessment. The empirical analysis shows that conflicting trajectories were present on double turn lanes without median-turn lane markings in the Philippines, which resulted to serious conflicts among the turning vehicles and negatively influenced the turning speed and saturation flow rate of the turn lanes. On the other hand, the turn lane markings in Japan, provided a positive impact to mobility and safety of the turning lanes. Moreover, it was also found that the geometric characteristics and traffic signal phasing scheme highly affects the capacity and safety condition of signalized intersections. 相似文献
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限速标志在对速度管控的同时,对运行效率也有影响。作者以嘉兴市G320-文昌路平面信号交叉口为例,结合实地调研与VISIIM模拟,运用前后对比法分析了该交叉口设置基本路段限速90 km/h和在进口前100米限速70 km/h及全段80 km/h限速两种限速情形下的行程时间、延误时间、排队长度及停车次数的差异。结果表明,在信号交叉口进口范围内设置较基本路段低的限速,对交通安全改善作用不大,还会在一定程度上降低运行效率。 相似文献