What is the purpose of alternating between high and low beams?
2 Answers
Alternating between high and low beams is used for nighttime encounters with oncoming vehicles, overtaking, etc. The purpose of switching between high and low beams is to serve as a warning. Below are additional details: 1. High beams: Should be turned on in conditions of poor visibility, such as on highways or rural roads. 2. Low beams: Should be used when visibility is good, as well as when encountering oncoming vehicles, following another vehicle, encountering pedestrians, or non-motorized vehicles. 3. Alternating beams: When overtaking large trucks, because they have large blind spots and high chassis, it is necessary to repeatedly flash the lights to alert the truck driver and ensure safety before overtaking.
Alternating headlights while driving is mainly to remind oncoming vehicles to turn off their high beams to avoid accidents. I remember when I used to drive long distances, I often encountered oncoming cars with glaring high beams on narrow roads. In such cases, I would flash my low and high beams twice to signal them to turn off their high beams, and once they adjusted, I would switch back. This approach is not only courteous but also prevents collisions caused by nighttime glare. In reality, in mountainous areas or during rainy and foggy weather when visibility is low, alternating headlights acts like signaling—simple and effective. Never underestimate this; safe driving starts with these small habits. I’ve tried it, and it usually works within one or two attempts—most drivers cooperate, making it a more reliable method than honking.
