What should a driver do if they encounter fog while driving?

When a driver encounters fog, reducing speed and using low beam headlights is the safest and most effective response. Fog can significantly reduce visibility, making it difficult to see other vehicles, road signs, and hazards. By reducing speed, a driver has more time to react to any unexpected obstacles or changes in the road conditions.

Using low beam headlights is crucial because high beam headlights can create glare and reflect off the moisture in the fog, which can worsen visibility. Low beams direct light downward and are less likely to cause glare, making it easier to see the road in foggy conditions. This combination of decreased speed and appropriate headlight use helps ensure the driver can navigate safely and avoid accidents in low-visibility situations.

Other options do not provide an effective approach to dealing with fog. Increasing speed tends to heighten the risk of losing control, while stopping on the side of the road can also be dangerous if visibility is extremely low—other drivers may not see a stopped vehicle in time to avoid a collision.