During what weather condition must headlights be used at all times?

Headlights must be used at all times during foggy conditions primarily because fog can greatly reduce visibility. The dense moisture in the air scatters light, creating a reflexive haze that can obscure not only your view of the road ahead but also make it difficult for other drivers to see your vehicle. Using headlights in fog helps to illuminate the road directly in front of you.

Moreover, it makes your vehicle more visible to others, which is crucial for maintaining safety on the road. When driving in fog, standard headlights can be less effective since the light can reflect directly off the fog, causing glare and further reducing visibility. For this reason, many drivers are advised to use low-beam headlights instead, as they provide better illumination close to the ground without causing excessive glare.

This rule highlights the importance of adapting driving practices to specific weather conditions to enhance safety for all road users.