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Driving in fog

Fog is one of the most treacherous conditions when driving. In many places, it can come suddenly without warning, especially in some industrial areas where there may be more pollution particles in the air, or areas near water courses, lakes or coastal regions. When the fog is particularly dense, it is hard to see other vehicles on the road, or even whether you are on the correct side of the road. Here are some valuable tips to help with driving in foggy conditions.

Slow down

When fog descends, you will have less visibility and much less time to react to other road users. You can help to minimise your road risks by slowing to a more suitable speed. It is essential to slow down steadily, as harsh braking when hitting a thick patch of fog may not give the following traffic time to react.

Fog lights on

All vehicles are fitted with fog lights, and you must know precisely where they are placed and how to turn them on. Not knowing, and trying to find them in a rush, is not good. It is also wise to check them regularly in the winter, as a blown bulb will give you a false sense of visibility. Fog lights are exceptionally bright and should only be used in limited fog visibility, or in a very heavy downpour with a lot of road spray.

Turn on your headlights

It is wise to turn on your headlights when encountering fog, but only on a dipped beam: full beam can illuminate the fog and bounce the beam back, giving no improved visibility. Many cars now have automated headlights that come on when the light is low, but with fog there can still be bright conditions and the lights may not come on automatically, so override them when necessary. Don’t just assume your vehicle will know it’s foggy.

Keep a safe distance

Always leave at least a 2 second gap between you and the vehicle in front in normal conditions; in fog this must be increased to at least a 4 second gap. This gives you much more time to react if they suddenly brake or swerve. People often unknowingly feel the urge to keep sight of the rear lights of the vehicle in front in fog. It gives a sense of security in a stressful situation, but it is dangerous: be aware of it. Also be aware that it is much harder to judge the speed of oncoming vehicles; someone may pull out in front of you because they hadn’t anticipated your speed and distance. This makes controlling your speed even more important.

Clear your windows

Fog usually occurs in damp weather and can cause excess condensation inside and outside your vehicle, so make sure your windscreen wipers are checked regularly and use them to clear the screen. When necessary, put the demist functions on and keep the heater warm, which helps keep the inside of the car dry and the windows clear of condensation. Driving with insufficient screen visibility can void an insurance claim and is very dangerous, the same as driving in a car covered in ice or snow.

Listen as well as look

In very dense fog, opening your window lets you hear road traffic, especially before turning into or out of a junction. An open window can also help with concentration. It is also wise to turn off the stereo until you have passed the fog bank and the road is clear again.

Postpone your trip

If you are aware of foggy conditions on your planned route, it is wise to postpone the journey. Working from home or rearranging a family visit is better than taking a risk with fog, especially if conditions worsen on the road.

Keep a winter kit in your car

A simple kit helps: a high viz vest and warning triangle in case you have to stop in an emergency, a torch, a mobile phone and charger, and water for the coolant and washer bottle. It is also wise to carry a warm blanket, water, and snacks in case you are waiting for recovery.

Switch off when clear

Once you have safely navigated through the fog, switch off your fog lights as soon as possible, as they cause glare for drivers behind. If you are used to automated lights, check they are off.