When driving in thick fog with very bad visibility, the safest option is to:

If fog becomes so thick that you can barely see, it is best to pull off the road, activate your emergency flashers, and stop. Wait to proceed until visibility improves. Do not creep along the road at a slow speed.

• Drive at a speed under 10 miles per hour.
• Use your high beam headlights.
• Pull off the road and stop, using your emergency flashers.
• Honk periodically.