How to drive in fog

The video above was created for a US audience. In the video you're urged to stay close to the right-hand lane marker so you don't stray into oncoming traffic. But in the UK, because we drive on the left, you need to stick to the left-hand lane marker instead.

When the temperatures drop, the air cools and fog often results. The result is reduced visibility – which is bad enough, but what’s even worse is when it’s patchy. One minute you can be driving with perfect visibility, and the next you can barely see the end of your bonnet.

The key – as ever – is to keep your speed down so you’ve got plenty of time to react to any hazards that might develop. But there’s also an array of other things you can do to make your life easier – and also the lives of those around you.

Here, we guide you through the things you need to do to stay alive next time you have to drive in fog:

  • Before setting off, clean your windows and windscreen and ensure all your lights are working.  Clean the inside of the screen as well; it can be hard to tell if your windows are misting up, as it looks just like the fog outside.
  • Switch on the heater or air conditioning and leave them running to keep the inside of the glass clear.  Air-con helps dry the air – on a foggy day it can really help.
  • Use your windscreen wipers on an intermittent setting to keep the screen clear; those droplets of moisture build up faster on your screen than you realise.
  • Always keep your headlights switched on, but stick to dipped beam as you’ll dazzle yourself on main beam. Don’t rely on your car’s daylight running lights – they tend to work only at the front of the car.
  • Use fog lights if visibility is less than 100 metres, but don’t forget to switch them off when visibility improves. And if you’re in stop/start traffic, keep them switched off or you’ll just dazzle the driver behind. Remember that rear fog lights may mask your brake lights, increasing the chance of somebody driving into the back of you.
  • Slow down and keep enough distance between yourself and the vehicle in front - make sure you can stop safely within the distance you can see clearly.
  • Fog is not the same density all the time – when it gets thicker, slow down.
  • Brake gently, and earlier than usual so your brake lights warn drivers behind that you’re there.
  • Be aware that other vehicles may be travelling without their lights on, and pedestrians and cyclists will be hard to see anyway, so extra care and attention is needed.
  • At junctions, wind the window down and listen for traffic.  If you have electric windows, open the passenger one to listen that way as well.
  • Straining to see through thick fog will quickly make you tired – take regular breaks.

* Also check out our page on the importance of maintaining visibility, as well as our page on how to deal with a skid.