Vehicles with fog lights

Have you been blinded by the light when unthinking drivers come up behind you with blazing front fog lights – or forget to turn off their rear fog lights when visibility improves.

There seems to be a certain amount of confusion about if and when fog lights, both front and rear, should be used. Yet the Highway Code quite clearly sets out how to drive safely in fog:


Fog (234 to 236)

Before entering fog check your mirrors then slow down. If the word ‘Fog’ is shown on a roadside signal but the road is clear, be prepared for a bank of fog or drifting patchy fog ahead. Even if it seems to be clearing, you can suddenly find yourself in thick fog.

When driving in fog you should

  • use your lights as required
  • keep a safe distance behind the vehicle in front. Rear lights can give a false sense of security
  • be able to pull up well within the distance you can see clearly. This is particularly important on motorways and dual carriageways, as vehicles are travelling faster
  • use your windscreen wipers and demisters
  • beware of other drivers not using headlights
  • not accelerate to get away from a vehicle which is too close behind you
  • check your mirrors before you slow down. Then use your brakes so that your brake lights warn drivers behind you that you are slowing down
  • stop in the correct position at a junction with limited visibility and listen for traffic. When you are sure it is safe to emerge, do so positively and do not hesitate in a position that puts you directly in the path of approaching vehicles.

You MUST NOT use front or rear fog lights unless visibility is seriously reduced as they dazzle other road users and can obscure your brake lights.

You MUST switch them off when visibility improves.

Law: Road Vehicles Lighting Regulations 1989: regs 25 & 27

NB: Seriously reduced visibility is classed as 100 metres or less

More about using vehicle lights in adverse driving conditions can be found in the Highway Code