Rules of the road
Lesson 9 · Night, weather and emergencies

Which lights should you use in fog?

Short answer

Low beams, plus fog lights if you have them. Slow down and leave extra space. High beams make fog worse.

Watch it play out

How to do it

  1. Turn on low beams and fog lights if you have them.
  2. Slow down so you can stop within the distance you can see.
  3. Increase your following distance.
  4. If you cannot see at all, pull completely off the road and turn on hazard lights.

Why the rule works this way

Fog hides cars ahead until you are close. Slower speed and more space give you time to react.

Common mistakes

  • Using high beams.
  • Stopping in the travel lane when visibility drops.

Questions people ask

Should I use hazard lights while driving in fog?

Rules differ. Some states ban hazard lights while moving, and others allow them in very low visibility. The safest plan is to pull fully off the road, then turn them on.