Roundabouts are a form of circular intersections adopted to secure road safety of the vehicles. However, collisions are not prevented entirely even when using roundabouts, since accidents may happen at specific intersection points leading to either traffic congestions or serious accidents. In this paper, a visible light communication (VLC)-based collision avoidance scheme is proposed to coordinate autonomous vehicles in traversing roundabouts, which has high effectiveness in vehicular environments. In particular, roadside units (RSUs) are deployed at the roundabout entrances to coordinate the vehicles in a vehicle-to-infrastructure (V2I) mode. By adopting the synchronization approach, vehicles can pass the roundabout simultaneously if their paths are concurrent with each other. Otherwise, vehicles are prioritized according to their arrival time and reasonable decelerations are applied to waive potential conflicts. Simulation results showed that our proposed approach satisfies the roundabout traffic demands in terms of concurrency, safety, and time utilization as vehicles are strongly recommended to decelerate in only 22% of the cases studied in different scenarios.

回旋处是一种圆形交叉口，用于确保车辆的道路安全。但是，即使在使用环形交叉路口时，也无法完全避免碰撞，因为事故可能会在特定的交叉点发生，从而导致交通拥堵或严重事故。本文提出了一种基于可见光通信（VLC）的防撞方案，用于协调自动驾驶汽车在环行交叉路口的情况，在车辆环境中具有很高的有效性。特别是，在回旋处的入口处部署路边单元（RSU），以车辆到基础设施（V2I）模式协调车辆。通过采用同步方法，如果车辆的路径彼此并发，则它们可以同时通过回旋处。除此以外，根据车辆的到达时间对车辆进行优先排序，并采用合理的减速度来避免潜在的冲突。仿真结果表明，我们建议的方法在并发性，安全性和时间利用率方面满足环岛交通需求，因为强烈建议仅在不同情况下研究的案例中，只有22％的车辆减速。