Main image for post: Driving in Fog: How to Use Your Lights CORRECTLY!

Driving in Fog 101

We hate to say it… But winter is on its way. During autumn, evenings get darker and the prospect of fog and mist is much more likely – making driving conditions much riskier. Even if you’re a confident driver, driving in fog can be daunting, as the reduced visibility can lead to dangerous or difficult situations.

So here’s the million-dollar question. Do you know how to use your fog lights correctly? Research shows that 1 in 3 people are unsure of exactly when they should be turning them on, and a whopping 1 in 6 don’t even know where they are! To help you out, we’ve written a handy ‘Which Lights and When’ guide for driving in fog.

Which Lights and When?

General headlights and dipped beams

Whenever you venture out in autumn, try and make a quick check of your lights before you leave. It sounds like a hassle but after a few times it’ll soon become a habit.

Turn on your lights to the ‘dipped beam’ setting and check that they’re all working on both sides, at the front and at the back.

If you have automatic headlamps, make sure these have activated – or better still, override them manually by turning the headlamp switch to the dipped beam setting.

On darker days, early morning or evening, or when conditions do start to get foggier, always make sure your headlights are actually on. Don’t just assume they already are. Many cars’ dials light up these days, even when the headlights are turned off, which can be misleading.

To improve vision, check the position of your headlamp switch and make sure it is set to the dipped beam setting. This will enable other drivers to see you in plenty of time when it’s a bit dingy outside.

Is brightest always best?

It’s easy to assume that foggy conditions mean that your brightest lights are the best bet – but in fact that’s not the case at all.

Using full beam headlights is actually more dangerous in fog, even when there’s nobody else around. This is because the fog actually reflects the light back at you, which then reduces visibility, rather than improving it. Always double check - if the little blue headlamp light is glowing on your dashboard, your full beams are switched on and they shouldn’t be.

So what about fog lights?

It’s a legal requirement that all modern cars come with rear fog lamps, so even if you’re not sure where they are, they’ll be there somewhere. If you don’t know how to turn them on and off, do a little research online. If you’re still not sure, check out YouTube – it’s highly likely there’s a tutorial for your make and model.

Make sure you find out at the earliest possible opportunity. The last thing you want is to be scrabbling around trying to find a switch just as thick fog descends on a country lane. It’s true it really does come out of nowhere!

Don’t forget: Fog lights will only work when your dipped beam headlights are turned on, so make sure you do that first before driving in fog.

When to turn them on

It’s important that you don’t turn your rear fog lights on any earlier than you need to, because you could end up dazzling any drivers behind you. According to The Highway Code, you should only use your fog lamps when the visibility drops below 100m.

It can be hard to work out how far that actually is, especially when you’re in the driving seat and you’re already stressed out because of the poor conditions. A good rule of thumb is to check – can you see the rear lights of the car in front of you? If you can’t, you should probably be using rear fog lamps.

It’s easy to tell when your rear fog lamps are on – just look for an orange lamp-shaped symbol, with horizontal straight lines intersected by one wavy line.

What about front fog lights?

These days, most models come with fog lights in the front too. These lights shine a low, wide beam which is designed to cut below fog and help you see where the edges of the road are. Unless the fog is extremely thick, these lights are not absolutely necessary.

On the dashboard, front fog lamps are indicated by a green lamp-shaped symbol with sloping straight lines and a wavy line.

Don’t forget to switch off again!

Fog tends to clear as quickly as it comes in, so don’t forget when it’s gone or you’ve driven out of it to turn your fog lights off again as soon as possible.  Otherwise, you run the risk of dazzling other drivers and endangering yourself and others.

It might seem a little annoying that in patchy fog, you should turn your fog lights off in the clearer patches, and on again when the fog gets thicker. But remember, these gadgets have been developed for a reason – road safety.

Still confused about when to use?

If you’re ever in any doubt about which lights to use, all you need to do is put yourself in the position of the other drivers (or pedestrians!) around you. Ask yourself what your car looks like to them, whether they can see you, and whether they might be blinded by any of your lights.

By staying patient, sensible and cautious, you’ll stand a better chance of being safe on Britain’s roads when driving in fog. Learning how to correctly use your fog lights will minimise the chances of having an accident, and help to make the UK’s roads a safer place – event when the weather isn’t exactly playing ball. For more driving tips and advice, check out our social media pages @cartimeBury or