Do You Know When to Use Your Car Lights?

23 July 2025

Your car’s headlights have a lot more uses than helping you see the road at night. As a motorist, it’s important to understand when, how and why you should use the different lights on your car for maximum visibility and safety. Doing so helps to keep you and other drivers safe on the road. 

To better understand your car’s lights and when to use them according to UK law, take a look at our complete guide below.

What are the different types of lights on a car? Car lights explained

There are several different lights on your car, with each one serving a specific purpose to ensure your safety out on the roads. Here’s a quick overview of the lights all drivers need to be aware of:

1. Dipped beam headlights

Dipped beam headlights are angled downwards towards the road, meaning there’s no risk of them dazzling other drivers. But when should you use your headlights? Well, these are the standard lights that are used when driving at night in poor visibility.

2. Full beam headlights

These are the brightest front-facing lights on a vehicle, and they are used on unlit roads to provide maximum visibility. If you’re wondering what lights to use at night, full beam headlights are typically required.

However, bear in mind that they’ll need to be turned off when you meet oncoming traffic or you’re following another vehicle.

3. Fog lights

Fog lights are designed to cut through foggy and misty conditions, increasing visibility to keep you safe. A rear fog light is a single or double red light, while front fog lights are smaller white lights that sit lower down on the bumper.

4. Hazard warning lights

Visible on all corners of your car, hazard lights are blinking amber lights that are used to warn drivers of a breakdown, accident, or obstruction. You should only use hazard lights if your vehicle is stationary.

5. Parking lights

Parking lights, (also referred to as sidelights) are small, white lights found under the front corners of your car. But when do you use sidelights? Well, because they are dimmer than headlights, they can be used when visibility is slightly reduced, such as at dusk.

6. Daytime running lights

Found on many modern vehicles, these are low-powered front lights that automatically come on when the engine is running. These running lights help improve the car’s visibility during the day.

Driving condition: Daytime

Many motorists think it’s only important to use their vehicle lights at night, but there are many instances when you should turn them on during daylight hours. 

Brake lights should come on as soon as the brake pedal is pressed, but not used continuously in stationary queues of traffic as this causes unnecessary glare for drivers behind the vehicle. 

When visibility is significantly reduced during the day, headlights and fog lights should be used. Once visibility improves, these lights should be switched off to avoid dazzling other drivers. In dull weather and heavy rain on motorways, dipped headlights can help you to be seen by others on the road. 

Driving condition: Night

According to The Highway Code, “night” refers to the period between half an hour after sunset and half an hour before sunrise. If you’re wondering when to use sidelights, all sidelights and rear registration plate lights must be lit between sunset and sunrise – even if there is ample street lighting. If in doubt, turn on the full beam headlights. 

The key when it comes to lighting your way at night-time is to have sufficient light to clearly see where you’re going and to ensure that you can be seen without dazzling other road users.

You should switch from full beam to dipped headlights when other road users are driving toward or in front of you. However, if you overtake a vehicle in front of you, you can then put your full beam lights back on to better illuminate the road ahead, provided there is no oncoming traffic.

Legally, you can use your sidelights at night if you’re driving under 30mph in a well-lit area.

However, most drivers use dipped headlights anyway for increased visibility on the road.

If you are on the receiving end of bright headlights, you should slow down or, if necessary, stop. A good way to avoid being dazzled is to look to the far left of the road and follow the white line.

Driving condition: Fog

How much fog warrants turning on your fog lights? The Highway Code states that you should use your rear fog lights if you can’t see more than 100m beyond your car. Before you get your tape measure out, a good way to assess this length is to use the car in front – if you are struggling to see their rear lights because of fog, then turn on your fog lights.

Although it’s not a legal requirement to use your fog lights, it is much safer for yourself and other motorists. However, you could receive a penalty notice if you leave your fog lights on when visibility is clear, so turn them off as soon as the fog has passed.

Driving condition: Rain

Rain can have a big impact on visibility (especially when combined with spray from other vehicles). If you’re unsure which lights to use when driving in conditions like this, a good rule of thumb is to use your sidelights or dipped beam headlights. These will help you see the road more clearly and ensure other drivers can see you.

We get our fair share of wet and windy weather in the UK, so make sure to check out our guide on how to drive safely in strong wind.

Don’t get caught out

Using your car lights incorrectly or being without fully working lights could land you in trouble. Here are some of the most common penalties:

• If you’re stopped by police for a brake light that isn’t working, you might be lucky enough to only get a verbal warning. However, you could get a £60 fine and 3 points on your license, a notice allowing you 10 days to replace the light, or have your car taken off the road immediately.
• If one of your headlights isn’t working, you could get a verbal warning, a £30 fine, 3 points and a £60 fine, or a notice allowing you 10 days to fix the issue.
• It’s illegal to drive with your fog lights on in clear weather. You could receive a Fixed Penalty Notice – no points but a £30 fine.
• Although there are no laws directly relating to the misuse of full beams, if you do have them on at the wrong time, you could get points on your licence for driving without care. The same goes for using your hazard lights incorrectly.

How to use your car headlights

Here are some final reminders on when to use your sidelights, headlights, and dipped beam lights:

• Turn on sidelights when visibility is low
• Daytime running lights are not a substitute for sidelights because they do not illuminate the rear of the vehicle
• Switch on the headlights when visibility is seriously reduced
• Use the fog lights when visibility is reduced to less than 100m by fog or spray
• Turn on the dipped beam headlights to avoid dazzling other road users when driving at night
• Turn on full beam headlights at night when the road ahead is completely clear – no oncoming traffic and no vehicles are in front of you

Using your car lights is really quite simple. Dipped lights are the brightest lights your car has that won’t dazzle other motorists. Therefore, get into the habit of always using them when visibility is poor, such as at dusk, at night and in bad weather. 

Turn on the full beam headlights when the road ahead is clear, but don’t use them in fog or heavy rain, as the beam pattern creates a wall of light instead of illuminating the road ahead. When the weather gets particularly bad and visibility is significantly reduced, you can rely on fog lights.

Remember to regularly check that all of your lights are working correctly. Any blown out bulbs could put you at risk on the road. You could get a friend to help you check your front and rear lights or take your car to your local garage.

Looking for additional insights? You’ll find plenty over on our blog. There you can check out our guide on the longest car manuals in the world or dive into some vehicle care guides. These are filled with everything you need to know about taking care of your car.