While other weather patterns like rain and snow come immediately to mind as driving challenges, driving in fog is one of the riskiest and most difficult challenges drivers face. According to The Weather Channel, fog occurs mainly in the early morning and in cool, wet weather, and it often overlaps with other hazardous conditions like darkness and winter weather, exacerbating the problem. According to some studies, the risk of accidents increases by as much as 40% when driving in foggy conditions.
As the New York Times described, “deadly multicar crashes generally occur when cars and trucks traveling at interstate speed drive into what is essentially a low-lying cloud and quickly lose visibility.” Unlike rain and snow, which affect the road surface, that loss of visibility affects the driver directly without necessarily compromising the driver’s feeling of control. As a result, many drivers are too confident when driving in the fog and don’t take the precautions necessary to be safe. Learn more tips for driving at night.
How to drive in fog
Low visibility due to fog means you have much less time to react to obstacles or other cars on the road. You may not be able to see a hazard until you’re right on top of it. The two most important things you can do in the fog are to slow down and make yourself as visible as possible.
To put the role of visibility and safe driving speeds into context, consider the three second rule. This common rule of thumb states that you should watch the car ahead of you. When it passes a stationary object, it should be at least three seconds before you pass that object. At speeds of 60 mph, that means leaving a little more than 250 feet between you and the next car. If your visibility is limited to 80 feet, for instance, the three-second rule will restrict you to a speed of around 18mph. Going faster means you may not have time to react to a stopped car or obstacle in front of you. That’s one of the reasons why fog is a factor in around 20% of crashes involving ten or more cars.
Making your vehicle visible is also essential. When driving in fog, you should turn on your headlights and use your fog lights (if you have them). Never turn on your high-beam headlights. High-beams point forward, directly into the fog, and tend to reflect light into your eyes and those of other drivers, making it harder to see.
Tips for driving in foggy conditions
Stay in the right lane
In foggy conditions, it’s best to stay in the right lane. Other drivers can’t see any better than you in foggy conditions, so your best bet is to follow the stripe at the edge of the road rather than follow the car in front of you. When you follow another driver, you risk running off the road if the driver ahead makes a mistake.
Turn off your cruise control too. Using cruise control while driving in fog makes it harder to stop quickly for another vehicle, wild animal, or another hazard on the road.
Keep a clear view
Low visibility due to fog is often compounded by moisture build-up on the windshield. Combat a cloudy windshield by running the defroster with the air conditioning and the system set to recirculate the air when driving in foggy conditions. The air conditioner pulls moisture out of the air, making it easier to defog your windshield in humid conditions.
What to do when the road is foggy
Consider pulling off the road. If the fog is especially dense and your visibility is severely reduced, it may be better to pull off the road and wait it out than to keep going. Other drivers will have difficulty seeing you when you pull over, so pull farther off the road than you normally would and turn on your hazard lights. Pulling off the road can also be a safe option in wintery weather. Learn more about what to do to stay safe when you are driving in snow.