Guide to Driving in Fog

Fog can dramatically reduce visibility, making your journey difficult and dangerous. If there are weather warnings for heavy fog before you set off, it’s best to wait until it clears or postpone your drive.

If fog is unavoidable or you come across it while on your way, you can do a few things to reduce your risks.

Before you set off

• Check the local weather forecast to know when and where to expect fog.
• Check your dipped beams and lights to make sure they’re all working.
• Fully charge your mobile phone, in case you need to call for help.
• Make sure your fuel tank is full.

Before entering fog

• Check your mirrors and start slowing down by gently braking to give the drivers behind enough warning.
• Stay vigilant if a roadside sign warns of fog ahead. Even if the road seems clear, fog may be lingering just out of view and could descend unexpectedly.

Driving in fog

• The Highway Code states that headlights must be used when visibility drops below 100 metres. Using your dipped beams will improve your vision of the road ahead and make you more visible to other motorists. Don’t use full-beam as this directs light up into the fog, making your vision worse.
• Front fog lights can give you a better view of the road ahead, while rear fog lights can help warn other motorists of your presence. To avoid dazzling other drivers, you should only use fog lights in thick fog. Make sure you switch them off as soon as visibility improves.
• Use your windscreen wipers and demisters to help reduce condensation.
• Pay attention and listen for other vehicles. Switching off the radio and opening the windows can help you hear other vehicles before you see them.
• Maintain at least a four or five-second gap between you and the vehicle ahead. Don’t use the rear lights of the vehicle in front as a guide. Doing so can give you a false sense of distance, leaving you without enough space to stop in time.
• Beware of other drivers who haven’t switched on their headlights.
• Don’t speed up if the vehicle behind you seems too close.
• When emerging from a junction in foggy conditions, don’t hesitate in a position that leaves you in the path of oncoming traffic.