← Driving in adverse weather conditions
Rule 235: When driving in fog
Advice, not law
Fog (rules 234 to 236)
When driving in fog you should
- use your lights as required (see Rule 226)
- 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.
Advice, not law. This rule is not written in capitals, so breaking it is not an offence in itself — but it can still be used in evidence in court to establish liability. The rules that say MUST or MUST NOT are the ones backed by law.
5 theory test questions on this rule
From the DVSA revision question bank. These are not the questions asked in the real theory test. Each one shows the answer, the explanation, and our own note on why every other option is not it.
Car
- You're following a vehicle on a wet road. You stay a safe distance behind it. What should you do if a driver overtakes you and pulls into the gap you've left? Safety margins
- You're following a large vehicle. Why should you stay a safe distance behind it? Alertness
- Other than direction indicators, how can you give signals to other road users? Rules of the road
- Why are vehicles fitted with rear fog lights? Vehicle handling