Ramp metering is one of the most effective tools to combat traffic congestion. In this paper, we present a ramp metering policy for a network of freeways with arbitrary number of on- and off-ramps, merge, and diverge junctions. The proposed policy is designed at the microscopic level and takes into account vehicle following safety constraints. In addition, each on-ramp operates in cycles during which it releases vehicles as long as the number of releases does not exceed its queue size at the start of the cycle. Moreover, each on-ramp dynamically adjusts its release rate based on the traffic condition. To evaluate the performance of the policy, we analyze its throughput, which is characterized by the set of arrival rates for which the queue sizes at all on-ramps remain bounded in expectation. We show that the proposed policy is able to maximize the throughput if the merging speed at all the on-ramps is equal to the free flow speed and the network has no merge junction. We provide simulations to illustrate the performance of our policy and compare it with a well-known policy from the literature.

翻译：匝道控制是缓解交通拥堵最有效的工具之一。本文针对具有任意数量入口匝道、出口匝道、合流与分流节点的快速路网，提出了一种匝道控制策略。所提策略在微观层面设计，并考虑了车辆跟驰安全约束。此外，每个入口匝道以周期方式运行，在周期内持续放行车辆，直至放行数量不超过该周期起始时刻的排队长度。同时，每个入口匝道根据交通状况动态调整其放行率。为评估该策略性能，我们分析了其通行能力，该通行能力由一组到达率表征，使得所有入口匝道的排队长度期望值保持有界。研究表明，若所有入口匝道的合流速度等于自由流速度且路网中不存在合流节点，所提策略可实现通行能力最大化。通过仿真验证了所提策略的性能，并与文献中一类经典策略进行了对比。