Fog Lamp
Fog Lamp emits a wide, horizontal, and sharply cut-off beam, and its light can be white or yellow. This lamp is intended for use at low vehicle speeds under adverse weather conditions such as rain, snow, fog, or dust, to increase illumination on the road surface. As a result, fog lamps are often used in place of the low-beam headlamps because they reduce light reflection from fog and snow. However, using fog lamps without low beams is generally against regulations.
When the driver’s visibility is not significantly reduced, the use of fog lamps is prohibited (for example, in the UK), because the glare can affect oncoming drivers and, on wet roads, excessive foreground illumination can reduce the driver’s own visibility. Due to misconceptions—such as the belief that fog lamps must always be yellow, and that any white light is a high beam—fog lamps and high beams are often confused. Automakers, aftermarket suppliers, and parts manufacturers frequently refer to these two lamps interchangeably.
In most countries, because foggy conditions are relatively rare, there is little strict requirement for using fog lamps. Consequently, turning them on is often for aesthetic purposes or as a substitute lighting option. Studies indicate that in North America, people tend to use fog lamps more frequently in normal weather than in rainy conditions.