What must you do when visibility improves after driving in fog?

Why that is the answer

You must turn off your fog lights as soon as visibility improves. High-intensity fog lights are very bright and can dazzle other drivers, especially those travelling behind you. They can also obscure your brake lights, making it harder for following drivers to see when you are slowing down. The Highway Code states you must only use fog lights when visibility is seriously reduced to less than 100 metres.

How this comes up in the real test

Questions from vehicle handling appear throughout the 50-question multiple-choice section, and the wording changes between versions. Learn the rule rather than the sentence: the DVSA can ask the same point from the opposite direction, and a memorised answer falls over the moment the phrasing moves.

The pass mark is 43 out of 50, so seven wrong answers is your entire margin. If a whole category is shaky, run the topic practice below until you are getting every question right for the right reason, then go back to full mocks under the clock.

More vehicle handling questions

• A lot of snow has fallen recently. When driving in these conditions, what are some things to think about?
• After fog has cleared, it can be dangerous to leave your rear fog lights switched on. What is the reason for this?
• What colour are the reflective studs along the left-hand edge of the motorway?
• During the day, when should dipped headlight be used?
• How can you regulate your speed with the engine of your car?
• How should you deal with this hazard?