To prevent local streets being blocked by overflowing on-ramp queues, a standard practice of ramp metering control is to restrain its function when a series of preset conditions are identified by on-ramp queue detectors. Such a trade-off between potential ramp queue spillback and the restraint resulting from the operation of metering control may often fail to either effectively mitigate bottlenecks caused by on-ramp waving or convince arterial users and local traffic agencies of the need for ramp metering operations. This study, therefore, presents an arterial-friendly local ramp metering system (named AF-ramp) that can achieve the target metering rate to produce optimal freeway conditions without ramp queues spilling back onto local streets. This is achieved by concurrently optimizing the signal plans for those intersections that send turning flows to the ramp. At this stage, this system has been developed for time-of-day control. It could also serve as the base module for extending to real-time control, or multi-ramp coordinated operations. The AF-ramp model, with its ability to optimize the arterial signals concurrently with the ramp metering rate, can ensure the best use of the capacity of local intersections and prevent any gridlock caused by overflows from on-ramp queue spillback or arterial turning traffic. With extensive simulation experiments, the evaluation results confirmed the AF-ramp model’s effectiveness in improving traffic conditions on both the freeway and its neighboring arterial links at the same time. This study has also introduced the real-time extension of the proposed model and a framework of a transition from the time-of-day control to fully responsive real-time operations.

为了防止本地街道被匝道队列溢出而阻塞，匝道计量控制的标准做法是在匝道队列检测器识别出一系列预设条件时限制其功能。在可能的匝道排队溢出和由计量控制操作引起的约束之间的这种折衷可能经常不能有效地缓解由匝道挥动引起的瓶颈，或者使动脉用户和当地交通部门无法进行匝道计量操作。因此，本研究提出了一种对动脉友好的本地坡道计量系统（称为AF坡道），该系统可以达到目标计量率，以产生最佳的高速公路状况，而坡道队列不会溢出到本地街道上。这是通过同时优化那些向匝道发送转向流的交叉口的信号计划来实现的。在此阶段，已经开发了该系统用于每日时间控制。它也可以用作扩展到实时控制或多斜坡协调操作的基本模块。AF匝道模型具有与坡道计量率同时优化动脉信号的能力，可以确保最佳利用局部交叉路口的能力，并防止由于匝道排队回溢或动脉转向交通溢出而引起的任何堵车。通过广泛的模拟实验，评估结果证实了AF匝道模型在改善高速公路及其相邻干线交通状况的同时的有效性。