Enhancing traffic flow plays an important role in the traffic management of urban arterial networks. The policy of prohibiting left-turn (PLT) at selected highly demanded intersections has been adopted as an attempt to increase the efficiency at these intersections. In this paper, we study the impact of PLT by mathematical analysis and simulations based on the cellular automaton model. Using the flow-density relation, three system performance indexes are examined: the average trip completion rate, the average traffic flow, and the average velocity of vehicles. Different route guidance strategies, including the shortest path and the quickest path, are investigated. We show that when left turn is prohibited, vehicles are distributed more homogeneously in the road network, and the system performs better and reaches a higher capacity. We also derive a critical length of link, above which the benefit of PLT will decrease.

中文翻译：

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禁止左转政策提高城市交通效率

增强交通流量在城市干线网络的交通管理中发挥着重要作用。为了提高这些交叉口的效率，已采用在选定的高需求交叉口禁止左转 (PLT) 的政策。在本文中，我们通过基于元胞自动机模型的数学分析和模拟来研究 PLT 的影响。使用流量-密度关系，检查三个系统性能指标：平均行程完成率、平均交通流量和车辆平均速度。研究了不同的路径引导策略，包括最短路径和最快路径。我们表明，当禁止左转时，车辆在路网中的分布更加均匀，系统性能更好，容量更大。