1993 Pontiac Firebird Owner's Manual - Page 158

When you drive into a fog patch, your visibility will be reduced quickly.The biggest dangers are striking the vehicle ahead or being struckby the one behind. Try to "read" the fog density down the road. If the vehicle ahead starts become to if less clear or, at night, the taillightsare harder to see, the fog is probably thickening. Slow downto give traffic behind you a chance to slow down. Everybody then has a better chance to avoid hitting the vehicle ahead. A patch of dense fog may extend only for a few feet (meters) or for miles (kilometers); you can't really tell while you're in it. You can only treat the situation with extreme care. One common fog condition - sometimes called mist or ground fog - can happen in weather that seems perfect, especially at night or in the early morning in valley and low, marshy areas. You can be suddenly enveloped in thick, wet haze that may even coat your windshield. You can often spot these fog patches or mist layers with your headlights. But sometimes they can be waiting for you as you come over a hill or dip into a shallow valley. Start your windshield wipers and washer, to help clear accumulated road dirt. Slow down carefully. Tips on Driving in Fog If you get caught in fog, turn your headlights on low beam, even in daytime. You'll see -and be seen -better. Use your fog lights if your vehicle has them. Don't use your highbeams. The light will bounce off the waterdroplets that make up fog and reflect backat you. Use your defogger. Inhigh humidity, even a light buildup of moisture on the inside of the glass will cut down on your already limited visibility. Runyour windshield wipers and washer occasionally. Moisture can build up on the outside glass, and what seems to be, fogmay actually be moisture on the outside of your windshield.