1993 Buick LeSabre Owner's Manual - Page 176

Fog can occur with high humidity or heavy frost. It can be so mild that you can see through it for several hundred feet (meters). Or it might be so thick that you can see only a few feet (meters)ahead. It may come suddenly to anotherwise clearroad. And it can be a major hazard. When you drive intoa fog patch, your visibility will be reduced quickly. The biggest dangers arestriking the vehicle ahead or being struck the onebehind. Try to by "read" the fog density down theroad. If the vehicle ahead starts to become less clear or, at night, if the taillights are harder to see, the fog probably is thickening. Slow down to give traffic behind you a chance to slow down. Everybody has a better then chance to avoid hitting the vehicle ahead. A patch of dense fogmay extend only for a few feet (meters) or for miles (kilometers); you can't really tell while you're in it. You can onlytreat the situation with extreme care. One common fogcondition -- sometimes called mist or ground fog-- can happen in weather that seems perfect, especially atnight or in the early morning in valley and low, marshy areas. You can be suddenlyenveloped 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 overa hill or dip into shallow valley. a Start your windshield wipers and washer, to help clear accumulated road dirt. Slow down carefully. Tips on Driving Fog in If you get caught in fog, turn your headlights on low beam, even in daytime. You'll see -- and be seen -better. Don't use your high beams.The light will bounceoff the water droplets that make up fog and reflect back at you. Use your defogger. In high humidity, even a light buildup of moisture on the inside of the glass will cut down on your already limited visibility. Run your windshield wipers and washer occasionally. Moisture can build up on the outside glass, and what seems to be fog may actually be moisture on theoutside of your windshield. Treat dense fogas an emergency. Try to find a place to pull off the road. Of course you want to respect another's property, but you might need to put something between you and moving vehicles -- space, trees, telephone poles, a private driveway, anything that removes you from other traffic. If visibility is near zero and you must stop but are unsure whether you are away fromthe road, turn your