Driving in heavy rain and fog

The UK is infamous for its ever-changing weather. We can go from blue skies in the morning, to black clouds by lunch - and still have time for a hailstorm, rain shower, and fog by bedtime. In this article, we’re sharing ways you can stay safe while driving through two particularly hazardous conditions - heavy rain and fog.

• Heavy rain
• Fog

Heavy rain

Heavy rain can reduce your visibility, traction, and braking power. 

1. Visibility

   When it starts to rain, turn on your windscreen wipers and sidelights. This will give you the best chance of seeing others around you, and them seeing you too. Changing your wipers annually will help to make sure they keep your windscreen clear, even in heavy rain.

2. Traction

   If you’re driving at speed, your tyres could skid across water, rather than pushing through to the tarmac below. This is called ‘aquaplaning’ and can be very scary. To avoid aquaplaning, the first thing you’ll need to do is slow down. Our article on driving tips for flooded roads includes more ways to stay safe.

3. Braking power

   It takes longer to stop on a road that’s wet, than one that’s dry. Lowering your speed and keeping a larger gap between you and the vehicle in front is key to avoiding accidents. Check out Rule 126 of the Highway Code for more details.

Fog

Driving in fog is particularly hazardous. You might find the road ahead of you disappears into a cloud of fog in seconds. There’s no way of dispersing the fog, but there are a few things you can do to try to stay safe and seen:

1. Lights on

   Your car will have rear fog lights – and maybe even front ones. When visibility gets so bad you can’t see 100m ahead of you (roughly the length of a football pitch), it’s time to turn on your fog lights.

   Remember to turn off your fog lights as soon as you leave the patch of fog. If you don’t, you may dazzle other drivers. visibility improves to avoid dazzling other road users.

   If visibility is reduced but not by enough to turn your fog lights on, your side lights or head lights will help other drivers to know you’re there.

2. Leave gaps

   Because of the lack of visibility, little hazards can become big problems, quickly. By leaving more space between you and the car in front, you’ll give yourself more time to react. Other road users may brake or turn unexpectedly – so by leaving a large gap, you should be able to continue travelling at a steady speed.

   Drivers may fall into a ‘convoy’ in thick fog, where vehicles follow each other, matching the speed of the car in front. If you’re in a convoy – especially if you’re at the front – avoid unnecessary braking, and indicate early for any turns you need to make.

3. Limits

   If visibility gets so poor you’re not confident you can keep driving, you’ll need to be very careful about finding a place to stop until the fog clears. Don’t brake sharply, don’t swerve your car, and make sure the place you choose to stop is well out of the way of traffic.

   Check your mirrors before you slow down, then brake gently, giving drivers behind you plenty of time to react to you slowing down. Indicate turns with plenty of notice, and maintain a large gap between your car and other road users.