Communication is essential for Cooperative Intelligent Transportation Systems (C-ITS) to achieve better road efficiency, especially for Autonomous Intersection Management (AIM) which coordinates vehicles to pass the intersection safely and efficiently. Communication delays cause severe safety crises (i.e., collisions) and vehicular-performance degradation regarding intersection capacities and vehicular delays. Targeting the delays, network researchers have been working on low-latency communication technologies, and C-ITS researchers have proposed delay-tolerant AIM systems to avoid collisions in intersections. The impacts of communication delays are observed and discussed in the literature; however, models and assessments of the delay requirements for AIM are needed to provide insights for future network and C-ITS research. Here, we model the impact of communication delays on vehicular performance at an autonomous intersection and validate the models with the simulation results from over two million experiments, two types of multi-lane intersections (a typical 4-legged intersection and a roundabout), and four AIM systems. The simulations are conducted with SUMO simulator and AIM systems, where communication delays are inserted into the message exchanges during the simulation. The models are represented in linear, quintic, and cubic polynomials, showing that communication delay between 0 to 100 milliseconds is linearly related to vehicular performance in terms of intersection capacity and vehicular delay. According to the models, we show that by reducing communication delay from 100 to 10 milliseconds, the capacity degradation can be reduced from 7-10% to 0.7-1.0%. Moreover, communication delays must be less than 247 milliseconds to allow AIM systems to outperform traditional traffic lights.

中文翻译：

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评估通信延迟对自主交叉口管理系统的影响


通信对于协作智能交通系统（C-ITS）实现更好的道路效率至关重要，特别是对于协调车辆安全高效地通过路口的自主交叉口管理（AIM）而言。通信延迟会导致严重的安全危机（即碰撞）以及交叉路口通行能力和车辆延误方面的车辆性能下降。针对延迟问题，网络研究人员一直致力于低延迟通信技术的研究，C-ITS研究人员提出了延迟容忍的AIM系统，以避免交叉路口发生碰撞。文献中观察并讨论了通信延迟的影响；然而，需要对 AIM 延迟要求进行模型和评估，以便为未来网络和 C-ITS 研究提供见解。在这里，我们模拟了自动交叉路口通信延迟对车辆性能的影响，并使用超过 200 万次实验、两种类型的多车道交叉口（典型的 4 路交叉口和环形交叉口）的模拟结果来验证模型，以及四个 AIM 系统。仿真是使用 SUMO 模拟器和 AIM 系统进行的，其中在仿真过程中将通信延迟插入到消息交换中。该模型以线性、五次和三次多项式表示，表明 0 到 100 毫秒之间的通信延迟与交叉路口容量和车辆延迟方面的车辆性能呈线性相关。根据模型，我们表明，通过将通信延迟从 100 毫秒减少到 10 毫秒，容量下降可以从 7-10% 减少到 0.7-1.0%。 此外，通信延迟必须低于 247 毫秒，AIM 系统才能超越传统交通信号灯。