I. Introduction
Roadside infrastructure units (RSUs) have become a vital component of many road networks around the world and an active topic of research [1], [2], mainly due to the widespread availability of inexpensive camera sensors. Early utilization of roadside infrastructure included poles and gantries equipped with camera sensors, which are used to monitor the traffic on the observed road. With the addition of different sensor types, the emergence of vehicle-to-everything (V2X) communication, and intelligent traffic lights and signage, more applications can be explored. These applications include traffic flow control, traffic warnings and congestion detection, traffic rule enforcement, road condition detection, obstacle and construction site warnings, and prioritization of public transport and emergency vehicles. At the same time, with the increasing availability of automated driving functions, trajectory prediction [3] and cooperative maneuver planning can now be realized, especially with assistance from RSUs, which is schematically shown in Fig. 1.