Driving in the winter months can be challenging, and fog often makes the dark mornings and evenings more dangerous. You therefore need to know how all the lights work on your car – including the fog lights.
When there is fog, you should have your headlights turned on. Many modern cars come with automatic headlights, which don’t always respond to foggy conditions. So you may need to switch them on manually.
The next consideration is whether to supplement your car’s headlights with fog lights.
What are car fog lights for?
The answer to the question sounds obvious, but bear with us. Rear fog lights are indeed for use in foggy conditions. But more importantly, they are for the benefit of other drivers. Their intense red glow won’t assist your own vision.
Like your indicators, they are a sign to other drivers that visibility is limited. And, of course, an indication that you are nearby.
When should I turn my fog lights on?
This is where things get hazy (so to speak) and it’s a subject of debate. Especially as inappropriate use of fog lights is a bugbear for many motorists.
Use the other cars around you as an indication of whether they are necessary. Look at the car 100 metres ahead and judge how visible it is. If you can see it clearly, fog lights aren’t needed. If the car is lost in the haze, with only glimmers of light to be seen, it’s definitely time to switch your fog lights on.
This is especially important on the motorway, given how fast you and other cars around you are travelling. Frankly, if conditions are that bad, we’d hope speeds will be below the 70mph limit. As soon the fog clears, though, it’s important to switch your fog lights off again.
What if I leave my fog lights on?
Fog lights have a very specific purpose. Using them when they’re not needed can dazzle other drivers, and even obscure other lights on your car. You don’t want the brake lights to be less visible because your rear fogs are outshining them.
It’s a legal issue, too. If the police see you driving with your fog lights on unnecessarily, a £50 on-the-spot fine could be issued.
How do I switch my fog lights on?
By law, all cars built since 1986 must have at least one rear fog light. This will be operated using a switch with a symbol similar to that on the left-hand side in the photo above.
Front fog lights aren’t a legal requirement, but many cars have them fitted as standard. In most cars, they can be switched on using the same stalk as the headlights, or via a button on the dashboard.
The symbol for fog lights varies. If the wavy line is to the left of the lamp graphic, those are your front fog lights. If the wavy line is to the right (as above), this activates your rear fog lights.
You will often see a warning symbol on the dashboard that confirms the fog lights are on.
Other tips for driving in fog
First of all, it’s usually beneficial not to use your main beam headlights. While it’s tempting to flick them on to give a better view, in thick fog it will cause reflections and reduce visibility even more.
Drive slowly, and leave a bigger gap to other vehicles in case they have to stop suddenly.
When you are stopped, for example at traffic lights, keep your foot on the brake pedal so your brake lights are lit up, making you more visible to other traffic. If a car stops behind you, though, use your handbrake and remove your foot from the brake pedal to avoid dazzling the other driver.
ALSO READ:
Winter is coming: how to prepare your car for the cold
The best new cars to buy in 2025
Your EV questions answered on Motoring Electric
