Fog can be thought of as a cloud at ground level. Fog can reduce visibility to 1/4 mile or less, creating hazardous driving conditions. If you cannot postpone your trip, drive with lights on low beam. High beams will only be reflected back off the fog and impair visibility even more. Reduce your speed and watch your speedometer. Fog creates a visual illusion of slow motion when you may actually be speeding. Listen for traffic you cannot see. Open your window a little, to hear for surrounding sounds. Use wipers and defrosters as necessary for maximum visibility. Use the right edge of the road or painted road markings as a guide. Be patient. Do not pass lines of traffic. Do not stop on a freeway or a heavily traveled road. If the fog becomes too thick that you can barely see, pull over completely off the road. Do not continue to drive until you can see well. When you are pulled over, remember to turn off your lights or someone may see your taillights and drive into you.