Long-distance driving involves more than following road signs and traffic rules. Drivers also use signals—such as indicators, hazard lights, and brief headlight flashes—to communicate with one another. One common exchange occurs when a car overtakes a large truck and moves back into its lane.
If a truck driver briefly flashes their headlights after you pass, they may be signaling that you are clear of the truck and can merge safely. The meaning can vary by driver and region, so treat the flash as a courtesy cue, not a substitute for
