What action should a driver take when driving in fog?

When driving in fog, using low beam headlights is the best action because they help improve visibility without causing glare that can reflect off the fog and obscure your view. High beam headlights tend to scatter light, creating a blinding effect that can hinder the driver's ability to see the road clearly. In contrast, low beams produce a more focused beam of light that stays closer to the ground, allowing the driver to see more effectively while minimizing reflections in the fog.

Turning off headlights completely or using parking lights only is unsafe, as it significantly reduces visibility and increases the risk of accidents. Drivers need to be visible to others on the road, and low beam headlights provide a necessary balance of illumination and safety when navigating in such conditions.