So much talk about LIDAR and other sensors. Why nobody talks about obvious idea of Road Object Message Bus? ROMB is a protocol where each road object (a traffic light, a sign, a car, etc.) can transmit info about itself. A car could broadcast its direction vector, intention to turn, any non ROMB moving object it sees. A traffic light could broadcast current state and when it is going to change. That additional information would greatly enhance overall security, especially during rain and snow conditions.

Self-driving is such important (just after eliminating combustion engines) that we could upgrade existing cars with cheap ROMB boxes. Vehicle GPS tracking system costs about $30. ROMB box would cost about $60.

Let's say a car ROMB received info about the white truck, while your car cameras and vision recognition systems see just a cloud and any truck in 50 m range, that conflicting info should cause the car to slow down.