What is the function of a car's width indicator light?
2 Answers
The function of a car's width indicator light is to indicate the presence and approximate width of the vehicle, facilitating judgment for other vehicles during passing and overtaking. Installed at the edges of the car's roof, these lights indicate both the height and width of the vehicle. Safety regulations require vehicles taller than three meters to be equipped with width indicator lights, which are white at the front and red at the rear, ensuring visibility to other vehicles during nighttime driving. Additionally, fog lights are commonly installed near or slightly lower than the headlights. Used in conditions of low visibility such as fog, snow, heavy rain, or dust, they serve as road illumination and provide signals to oncoming traffic. Fog lights typically emit yellow light with longer wavelengths, offering excellent fog-penetrating performance.
I often drive long distances, especially on highways at night, where the role of side marker lights is crucial. They illuminate the sides of the car, such as the small lights near the front and rear lamps, clearly marking the vehicle's width and position. This way, in darkness, fog, or rain, other drivers can see the size of my car from afar, avoiding misjudging distances or accidental collisions. Once, while driving on a foggy mountain road with poor visibility, I relied on these side marker lights to maintain a safe distance from other vehicles, preventing potential accidents. I also recommend regularly checking if the bulbs are burnt out, as sudden failure could pose risks. When parked on the roadside, I keep them on to alert pedestrians, but remember to turn them off to save battery. These small details genuinely enhance driving safety.
