What lights must a driver use in dense fog?

In dense fog, it is recommended that a driver uses dipped headlights and rear fog lights. Dipped headlights help illuminate the road directly in front of the vehicle without causing excessive glare that can reflect off the fog, which would hinder visibility. This lighting allows the driver to see better without overwhelming the driver of oncoming traffic.

Rear fog lights are specifically designed to make a vehicle more visible from behind in adverse weather conditions. The use of these lights is crucial because they are brighter than standard tail lights and can help other drivers see your vehicle amidst the fog, thus reducing the risk of collisions.

Using high beam headlights can create a wall of light that reflects off the fog and reduces visibility, while side lights alone do not provide adequate illumination for driving in dense fog. Thus, the combination of dipped headlights and rear fog lights is the proper choice for enhancing visibility and safety in such conditions.