How many times should the high and low beams be alternated?
2 Answers
No less than twice. During the lighting test, when you hear voice prompts such as: approaching a sharp curve, approaching a slope, approaching an arch bridge, approaching a crosswalk, or approaching an intersection without traffic signals, you should alternate between high and low beams no less than twice. Here is additional information: 1. The Road Traffic Safety Law stipulates: when driving at night, drivers must alternate between high and low beams in situations such as sharp curves, slopes, overtaking (while also turning on the left turn signal), arch bridges, crosswalks, and intersections without traffic signals; additionally, when overtaking at night, you must not only turn on the turn signal but also use the high and low beam alternation to alert the vehicle ahead; when approaching a crossing, you must use the high and low beam alternation to alert vehicles on both sides of the intersection. 2. Signaling oncoming vehicles to switch to low beams: In fact, when driving on urban roads, the vast majority of high and low beam alternations are used to signal vehicles in the opposite lane to switch to low beams. This is because during nighttime encounters between two vehicles, high beams can cause intense glare, dazzling the other driver and compromising driving safety, and also affect the visibility of pedestrians on both sides of the road.
When I encounter a slow-moving car ahead and want to overtake, I usually gently flick the light switch lever once or twice. This makes the high and low beams alternate a few times, serving as a friendly reminder for the car ahead to give way. Don’t flick it too many times—if the other driver misunderstands or you get distracted, it could be dangerous. Safety always comes first, especially during nighttime overtaking, which is inherently riskier. From my personal experience, on mountain roads, flicking the lever just once or twice works best; any more can startle the other driver like sudden braking. Modern cars all have this feature—it’s simple and reliable to operate—but make sure your lights are functioning properly by checking the bulbs regularly. In short, every flick should be decisive to avoid disrupting your driving rhythm.
