Motorists can also get such a flash.
The signal is primarily used between truck drivers. However, you may also encounter it as a car driver. This happens, for example, when you are traveling with a caravan or trailer. With just a passenger car, you can usually clearly see when you have passed a truck. With a caravan behind the car, that is much more difficult. Your vehicle combination is suddenly several meters longer.
A truck driver may therefore also briefly signal to you with his headlights. By doing so, he lets you know that not only your car, but also your caravan, has passed him. This occurs regularly on busy German motorways, for example. However, this does not mean that you must immediately steer to the right. Always check your own mirrors first. You alone remain responsible for a safe lane change.
Sometimes a thank you follows.
Anyone paying close attention may see something else happen after the light signal. Truck drivers regularly thank each other for this help. For example, a driver who has moved back to the right might briefly use their hazard lights. Sometimes, the left and right turn signals are also used for just a moment. By doing so, the driver is essentially simply saying: thank you.
