overtaking driver better judge the position of the truck and determine when the maneuver is complete.
But this kind of road communication is not limited to truck drivers; drivers towing trailers or caravans can also benefit from the same type of signal.
Motorists Can Also Encounter This Signal
The informal signal is often associated with communication between truck drivers, but motorists may also encounter it. This can happen, for example, when you are traveling with a caravan or trailer.
With a passenger car alone, you can usually see relatively clearly when you have passed a truck. With a caravan or trailer behind the car, however, the vehicle combination is several meters longer, making it harder to determine exactly when the entire combination has cleared the truck.
A truck driver may therefore briefly signal with the headlights to indicate that not only the car but also the caravan or trailer has
