Fog is arguably one of the most difficult conditions to drive in so it is important to make sure you are fully prepared. Below are some best practice tips from the Institute of Advanced Motorists (IAM) on how to drive in foggy conditions.
Before setting off, clean your windows and windscreen inside and out. This will clear off any residue or moisture which may affect your visibility. Ensure all your lights are working.
When you’re ready to leave, switch on the dipped headlights. Use front and rear fog lights if visibility is less than 100 metres, but remember to switch them off when visibility improves – leaving fog lights on when headlights would be adequate is an offence. It can also dazzle and confuse other road users – so it’s important to be considerate and switch off the fog lights in good time.
Use your windscreen wipers on an intermittent setting to clear moisture. Keep your windscreen washer topped up with screen wash. In freezing fog pure water will freeze on contact with the screen.
Switch the heater or air conditioning on and leave it running to keep the inside of the glass clear.
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 to be clear. Following a larger vehicle like a bus or a lorry can be beneficial as they are easier to see and will generally have better visibility than you do, but don’t follow too closely.
You still need to concentrate on what’s going on around you. And be aware that fog is not the same density all the time – it may get thicker, so slow down if it does.
Brake gently but earlier than usual so your brake lights warn drivers behind.
Be aware that other vehicles may be travelling without their lights on, so extra care and attention is needed. At junctions, wind the window down and listen for traffic.
Straining to see through thick fog will quickly make you tired – take regular breaks.
If you can’t see well at a junction, wind the window down and listen out for the traffic before pulling out.
Take high-viz clothing in case you have to leave the car.
Don’t underestimate the effect fog has on your visibility. Adjusting your driving to the weather conditions will help you to become a safer and more confident driver through the winter months.