Q: I would like to know more about when to use foglights. What does the law state? Vivienne Humphreys
A: The Highway Code states that you must use your headlights when visibility is reduced – generally when you cannot see further than around 100 metres (328ft).
The Code also states that you must not use front or rear foglights unless visibility is seriously reduced, and ensure you switch them off when visibility improves to avoid dazzling other road users.
Incorrect use of rear foglights can also obscure your brake lights, making you more vulnerable to a rear-end shunt.
Some police forces impose a fine of £30 for having your foglights on when conditions do not warrant their use.
Front foglights often have levelling adjusters, and aim lower than headlights to light up the road rather than the fog. Using them in conjunction with your dipped beam is normally the most effective strategy, because full beam can create a dazzling effect in thick fog.
Aftermarket bulbs with a yellow tint are available for headlights and foglights, and are claimed to offer reduced glare.