1993 Buick Riviera Owner's Manual - Page 170

Don't use your high beams. The light will bounce off the water droplets that make fog and reflect back at up you. Use your defogger.In high humidity, even a light buildup of moisture on the inside the glass will cut of Run down on your already limited visibility. 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 the outside of your windshield. T r Treat dense fog as an emergency.y to find a place to pull off the road. Of course you want to respect another's property, but you might need put something to between you and moving vehicles-- space, trees, telephone poles, a private driveway, anything ,that removes you from other traffic. must If visibility is near zero and you stop but are unsure whether youare away from the road, your tu_m lights on, start your hazard warning flasher, and sound your horn at intervals or when you hear approaching traffic. Pass other vehicles in only if you can far enough fog see ahead to pass safely. Even then, be prepareddelay to your pass if you suspect fog is worseup ahead. If the other vehicles try to pass you, make it easy for them.