Safe driving and emergencies
You must drive through heavy fog. Which lights should you use?
- Low-beam headlights. Correct answer
- High-beam headlights, to see farther.
- Parking lights or fog lights only, to reduce glare.
Why
In fog or heavy smoke, high beams do the opposite of what you want: the light reflects back off the droplets and creates glare in front of you. Use your low beams. Driving with only parking lights or fog lights is never allowed. Better still, the handbook suggests postponing the trip until the fog clears. If you must drive: go slowly, make sure you can stop within the distance you can see, increase your following distance, use your wipers and defroster, avoid changing lanes or passing unless absolutely necessary, and listen for traffic you cannot see. If it gets too thick to drive safely, pull off the road, turn on your emergency flashers and wait.
Where this comes from
California Driver's Handbook, DL 600 ENGLISH (REV. 6/2025). The correct answer is Low-beam headlights..