共查询到18条相似文献,搜索用时 718 毫秒
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在城市道路交通系统中。交叉口是道路网中通行能力的瓶颈和交通事故的高发区域,随着交通量的日益增大。T形交叉口交通效率越来越低。通过对T形交叉口3相位信号配时设置方法进行研究来提高T形交叉口运行效率。分析了T形交叉口交通冲突特性,提出了T形交叉口信号相位设置的相关建议。通过对现行十字彤交叉口信号配时公式进行改进,取得更加适合T形交叉口3相位信号配时方法,并结合工程实例,对此方法进行阐述。此信号配时改进方法对T形3相位交叉口信号配时,具有一定的实用性。 相似文献
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针对城市道路中常见的T型交叉口,该文详细分析了T型交叉口的相位设计类型.应用信号配时优化软件Synchro对具体路口进行设计优化及评价,提出了相关的结论及建议,希望对T型交叉口的设汁、优化及改造工作提供一定的参考. 相似文献
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针对传统单点交叉口信号配时方法对于过饱和状态下瓶颈交叉口不适用的情况,定义了排队紧张系数并提出了基于排队紧张系数的瓶颈交叉口信号配时方案,讨论了过饱和状态下最佳周期时长的计算;用实测交叉口数据进行VISSIM仿真,对比分析了传统信号配时方案和基于排队紧张系数的配时方案的效果,结果表明基于排队紧张系数的配时方案对瓶颈路段排队强度的改善有非常明显的作用. 相似文献
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为提高整个路网的通行效用,根据周期时长、相位绿信比与机动车延误特征,建立周期波动动态信号配时的非线性规划模型.信号控制系统根据路网中各路段机动车的流量特征,进行动态调整信号周期时长和各相位绿信比的最优配置,从而合理分配各进口车道的通行权.结果表明:运用动态信号配时法和固定信号配时法交通分配的结果基本一致,运用动态信号配时法与固定信号配时法相比,动态信号配时法使机动车在十字交叉口上效用提高10%左右,在T型交叉口上效用提高30%左右,较好地适应各种交通状态的变化.在非机动车交通量较小的交叉口,动态信号配时有利于非机动车通行效用的提高;而在交通量较大的交叉口上,动态信号配时对非机动车的通行效用有较小量的波动. 相似文献
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混合交通流条件下信号交叉口配时优化设计 总被引:10,自引:2,他引:10
运用适合我国交通现况的定时式线控制系统理论,以南京市太平北路与珠江路的十字典型交叉口为例,在现状调查分析的基础之上,具体分析信号配时方案产生的全过程,提出使城市道路单点信号控制交叉口的时空资源得到综合优化利用的交叉口车道渠化方法和信号配时优化方法,并应用交通仿真模拟软件VISSIM对交叉口配时方案进行模拟,将优化方案与现状进行比较,取得了较好的结果。 相似文献
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连续流交叉口是一种非常重要的非传统交叉口设计,通过将主交叉口左转车流转移至次级交叉口的方式,实现主交叉口二相位控制,从而大大提高主交叉口的通行效率。为进一步发挥连续流交叉口的通行性能,对主次交叉口的信号协调控制展开理论研究,提出了一种具有普遍适应性的信号配时优化模型。该配时优化模型能够有效协调主次交叉口的信号配时,最大限度地降低车辆延误、改善交叉口通行能力,生成理想的协调配时方案,在实际应用中,能够确保主次交叉口的可靠运行。在分析连续流交叉口延误的组成和性质的基础上,深入研究了交通流延误和排队随主次信号相位差的变化情况,做相应的场景分析,再通过主次交叉口相位差优化分析,给出了最优相位差的求解方法,大大简化了模型的求解流程。最后,以南昌市某干道交叉口为例,对其进行了连续流交叉口渠化设计,利用所建立的优化模型求解协调配时方案,再通过微观仿真平台进行了交通效益评价。结果表明:所生成的配时方案能够有效降低延误和车辆排队,改善交叉口通行能力;模型计算结果与仿真输出结果相符,进一步说明该信号配时优化模型准确、可靠。 相似文献
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《国际交通安全学会研究报告》2022,46(3):307-321
In recent years, significant research has focused on traffic safety evaluations at unsignalized intersections due to complex and heterogeneous traffic movements as well as driver behaviour at such locations. However, at unsignalized T-intersections, priority traffic rules are less respected, which creates more conflicts. Further, multiple traffic movements such as right turns and through movements with varied driver behaviour results in increases the severity of conflicts. Many research studies have focused on the proactive safety measures in traffic safety evaluations as compared to crash-based analysis. Also, it is observed that Time to Collision (TTC) and Post Encroachment Time (PET) are the predominant types of surrogate safety measures in traffic safety evaluations. From the existing research outcomes, it is understood that these surrogate safety measures may give a better understanding of chain events for crash occurrences, collision mechanisms, and resulting consequences. However, further research is required in order to understand the suitability of such surrogate safety measures based on the complexity of heterogeneous traffic as well as driver behaviour with considerations of turning vehicles, particularly at T-intersections. In this context, this paper critically reviews the recent developments in Surrogate Safety Measures (SSM) and their applications at unsignalized intersections, with a particular focus on the T-intersection. This paper also brings attention to T-intersection safety evaluation with SSM in a developing country context. The outcome of the present study is more useful in the evaluation of traffic safety at T-intersections and suitable safety indicators for the evaluation. 相似文献
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对清华东路与双清路丁字交叉口上下班高峰期的机动车、非机动车和行人流量及信号灯配时进行调查,针对该交叉口存在的道路过窄、信号灯配时不合理、非机动车及行人流量大、道路标志标线不明确等问题进行分析,提出拓宽道路宽度、增加非机动车车道、对信号灯配时相位进行优化等方案,最后运用Synchro仿真软件对改造前后的交叉口进行模拟仿真,模拟仿真结果表明改善方案可行。 相似文献
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为了更合理地评价无信号控制 T 形交叉口的安全水平,研究在交叉口类型划分的基础上,提出1种以交通冲突数的概率分布为评价指标的安全评价方法。其中,交通冲突数的均值和分布分别采用广义线形模型和泊松分布描述,在广义线形模型中,交通冲突数的均值为被解释变量,冲突交通流的交通量为解释变量,根据交通冲突数的均值估算,计算交通冲突数的泊松分布的概率。在利用实测数据对广义线形模型的参数进行标定后,根据主路直行与非直行交通流量之间的差异性,进一步提出了简化模型,将主路直行交通的影响简化为影响系数,并根据流量不同划分为4个等级,通过分析交通冲突数的概率计算值与安全阈值数的概率临界值之间的关系,进行无信号控制 T 形交叉口的安全评价。最后通过实际案例,对模型的可操作性和准确性进行了检验。研究表明,非直行流向流量较直行交通流量对交叉口安全水平的影响更大,利用文中所提出的简化模型,可重点调查其它流向流量,而主路直行交通流量只需观测其流量大致范围即可,平均工作效率提升25%。 相似文献
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Agent-based approach is a popular tool for modelling and developing large-scale distributed systems such as urban traffic control system with dynamic traffic flows. This study proposes a multi-agent-based approach to optimize urban traffic network signal control, which utilizes a mathematical programming method to optimize the signal timing plans at intersections. To improve the overall network efficiency, we develop an online agent-based signal coordination scheme, underpinned by the communication among different intersection control agents. In addition, the initial coordination scheme that pre-adjusts the offsets between the intersections is developed based on the historical demand information. Comparison and sensitivity analysis are conducted to evaluate the performance of the proposed method on a customized traffic simulation platform using MATLAB and VISSIM. Simulation results indicate that the proposed method can effectively avoid network oversaturation and thus reduces average travel delay and improves average vehicle speed, as compared to rule-based multi-agent signal control methods. 相似文献
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