A Survey: Why and How Automated Vehicles Should Communicate to Other Road-Users

Eye contact and gestures between road-users (including vehicle drivers, pedestrians, and cyclists) have contributed to road safety for a long time. For example, drivers of vehicles at intersections use eye contact and gestures to cyclists/pedestrians to indicate their intentions to ensure safety and orderly interactions. On one hand, automated vehicles could use wireless communications for various connected services, such as to exchange locations/speeds/directions between neighboring vehicles for crash avoidance, to acquire detailed road shapes for automated driving, and to be driven via remote control. It is important to ensure that all communications previously provided by drivers' eye contact and gestures can be implemented on proposed automated vehicles with connected services (connected-automated vehicles). Furthermore, we have to note that connected-automated vehicles have to communicate with many other road-users without communication devices in the initial phase of deployment. In this report, we first categorize road-users' eye contact and gestures into multiple groups. Next, we introduce proposed connected services and wireless communications (such as DSRC (Dedicated Short Range Communication), mobile-communication, and millimeter wave) for connected- automated vehicles. Finally, we discuss the vehicle lighting communications to cover communications previously provided by eye contact and gestures. The report concludes by discussing the deployment challenges of this approach in the real world.