To be seen is your responsibility while driving
The ability to see where you're driving is one of the most important factors in driver safety. But are you doing everything you can to be seen by other drivers? One of the threats to clear vision that might face any driver is high humidity that will cause condensation of fog on inside glass surfaces. You should be alert for this situation, which is hardly perceptible as it starts but soon builds up to block your vision. At the first sign of condensation on the inner surface of the windshield, turn on the defroster and open a side window slightly. The air conditioner should be turned on, regardless of temperature, to dry out the atmosphere. In extreme conditions wipe the inside glass surfaces. Outside fog, the natural variety that often obscures all vision along highways, can be really dangerous and calls for the utmost caution. The first light patch of fog you encounter can be a fortuitous warning which tells you to slow down; because it lets you know that fog conditions exist.
You never know when light fog can suddenly turn into dense fog, the “pea soup” kind that blinds every driver on the road and often results in multiple crashes and long pile-ups caused by inattentive drivers. Good driver slow down when clear vision is obscured by fog. Even in daylight turn on low beam headlights, mainly to help other drivers know you're there. High beam is not used, because the particles of moisture in the fog act like a reflectorized sign, reflecting the more intense light, with its higher reflectance angle, right back into the driver's eyes. If the fog becomes dense, the cautious driver slows to a crawl, or pulls onto the shoulder as far off the road as possible and stops altogether—turning on the flashing warning lights to warn other drivers.
Many drivers seem to need reminders about the deceptive illumination at dusk. At this period, daylight is fading, yet it may not seem dark enough for headlights. After driving for some time in normal daylight, hazards along the way are no longer clearly defined by the twilight. This is the time to turn on headlights—low beam—to help you to see clearly and to help oncoming drivers see you. They may also be fooled by the twilight, and they need to know that you're there. When you drive east at sunrise, or west at sunset, you have another visibility problem. The sun's glare is right in your eyes, and you must take special precautions. At such times, you should use sun visors and sunglasses, and slow down until you're in command of the situation. But if the sun is at your back, remember that oncoming drivers have the sun in their eyes and may not readily see you. Headlights should be turned on whenever weather reduces visibility. These, will make your vehicle more visible to other drivers.
If the change in weather means rain, snow or sleet, you have other aids to visibility in your windshield washers and wipers. Some drivers seem loath to turn on their wipers for the first few drops of rain because the mixture of dust and moisture will mean a smeared windshield. That's when washers prove their worth. A few squirts of the washer fluid will clear the smear so the wipers can take care of rain. Drops of rain on windows may distort what you see through your rearview mirrors, so check more carefully than usual when this happens. If you're not certain you are seeing clearly as you pull into another lane or prepare for to turn, you should open your window enough to get a clear view. This is especially important at intersections, where you must make sure about traffic coming from both directions. Take a second look...and a third look. Don't depend on fast acceleration to get you out of the path of a vehicle you didn't see soon enough. Your tires may spin on the wet road surface.