When To Use Dipped Headlights & Car Light Rules UK

Headlight use has been in the spotlight recently, after the Driver and Vehicle Standards Agency (DVSA) issued a reminder about Highway Code Rule 226 - specifying that you must use headlights when visibility is seriously reduced, generally when you cannot see for more than 100 metres. With one in seven admitting they don’t use headlights when it’s hard to see, it’s clear there’s still confusion around correct light use.

According to research by Aviva: 

• 14% of drivers fail to use headlights when visibility is reduced, and 
• 49% use rear or fog lights at any time of the day, even when it’s inappropriate for visibility. 

To help clear things up, we’ve explained exactly what the Highway Code says about headlights and other car lights, and when each should be used to stay safe and visible on UK roads. 

Highway Code headlight rules

The Highway Code sets clear rules on when and how to use your car’s lights. These regulations apply to every driver in the UK, whether you’re on rural roads, motorways, or city streets, and are designed to maintain visibility and prevent glare. 

Under the UK’s Highway Code: 

• You MUST use headlights when visibility is seriously reduced, generally defined as when you cannot see more than 100 metres (328 feet) ahead. 
• All sidelights & registration plate lights have to be lit at night – which is classed as 30 minutes after sunset until 30 minutes before sunrise. 
• Front and rear fog lights may also be used in these conditions, but must be turned off as soon as visibility improves. 
• You must not use any lights in a way that dazzles other road users. 

This advice comes directly from the official rules covering adverse-weather lighting, and reinforces the legal requirement to adjust lights according to conditions - not just the time of day. 

Types of headlights & car lights

Every light on your car serves a different safety purpose; some help you see the road, while others help others see you. Knowing when and how to use each correctly is key to staying visible and complying with the Highway Code.

Daytime running lights (DRLs)

DRLs automatically activate when your engine starts, and are now fitted as standard on all new cars sold in the UK. They’re designed to make your vehicle more visible to other road users during daylight hours, but don’t illuminate the road ahead or activate your rear lights - meaning your car can still be hard to see from behind in low-light conditions. 

Use DRLs: 

• During the day, to increase visibility 
• But still switch to headlights when visibility worsens (e.g. dusk, rain, fog) 

Important: Don’t assume DRLs replace dipped beam headlights; they’re designed only to make your car more visible during daylight.

Sidelights

Sidelights don’t provide forward illumination, so they should be combined with headlights when driving on unlit roads. While they don’t offer much in the way of improving your visibility, they make it easier for other drivers to see you. 

• Used to make your car visible at night or in poor weather 
• Required if it is dark or visibility is reduced, even if street lighting is present

Dipped beam headlights

Also known as low beams, dipped beam headlights provide forward visibility at night or in poor weather without dazzling other road users. 

Use a dipped beam when: 

• It’s dark (night or dusk/dawn) 
• Visibility falls below clear conditions (rain, fog) 
• You need to be seen without causing glare 

If your car has automatic lights, always confirm they are functioning correctly before driving. 

Full beam headlights

Full beams offer maximum illumination, but can easily dazzle other drivers. 

Use full beam when: 

• On unlit roads with no vehicles ahead 
• Visibility is low and no other traffic is around 

You should only use your full beams when there aren’t any cars ahead of you. Switch back to dipped when you see an oncoming vehicle or are following another car within sight distance.

Fog lights (front & rear)

Fog lights are strong beams for extremely poor visibility, to help you drive in difficult conditions. 

Use fog lights only when: 

• Visibility is seriously reduced (e.g., thick fog) 
• Headlights alone aren’t enough 

Always switch them off when visibility improves, to avoid dazzling drivers and obscuring your brake lights. 

Indicators & Hazard lights

• Indicators signal lane changes, turns, and overtaking intentions. 
• Hazard lights warn of danger or obstruction (e.g., breakdowns) but should not be used for illegal parking. 

Be sure to avoid using hazard lights for any other reasons, as they can obscure your brake lights.

Brake lights

Brake lights automatically illuminate when you apply the brakes. 

In heavy stop-start traffic at night – especially in wet, glary conditions – it can be good etiquette to engage the handbrake and take your foot off the brake pedal so that the drivers behind you don’t get the glare, but this depends on the context of the situation. 

Why proper headlights use matters

Using your lights correctly isn’t just about legal compliance; it’s a crucial part of safe, considerate driving. Poor lighting reduces your visibility and makes it harder for others to judge your position and speed. 

Research by Aviva found that 55% of UK drivers may be using their lights incorrectly, putting themselves and others at risk. Proper lighting ensures that you can see clearly, be seen early, and avoid dazzling other road users, especially in rain, fog, or after dark. 

In short, using the right lights at the right time is one of the simplest ways to make every journey safer.

Headlight FAQs

Q: How do you turn on your headlights?

A: In most cars, rotate the lighting dial near the steering wheel to the headlight icon, or set it to auto mode if this is a feature on your car. Always confirm lights activate when conditions demand.

Q: Which headlight setting should I use at night?

A: Use dipped headlights unless you’re on an unlit road with no other traffic, when full beams are appropriate.

Q: When to use full beam headlights in the UK?

A: You should use full beam headlights when driving on dark, unlit roads with no cars ahead or approaching. Make sure you switch to dipped when other vehicles are nearby.

Q: Should you use the main beam in fog?

A: No, a full beam can reflect off fog and reduce visibility. Use dipped plus fog lights instead.

Q: What's the difference between dipped and main beam?

A: Dipped beams provide moderate forward light without dazzling; main beams provide maximum forward light but can dazzle others.

Q: At what distance should you switch to low beams?

A: When visibility ahead is severely reduced, generally under 100 metres according to Highway Code Rule 226.

Q: Is it illegal to drive with your full beams on?

A: It’s not illegal per se, but using them in a way that dazzlingly affects other road users can breach Highway Code guidelines.

Q: How do you aim your headlights correctly?

A: Headlights should be aligned per your vehicle manufacturer’s guidance, often involving a level surface and specific adjustment screws or a garage check.

Having trouble with your headlights?

Your car lights play a vital role in keeping you (and everyone else on the road) safe. Using them correctly helps you see clearly, stay compliant with the Highway Code, and avoid dazzling other drivers in poor conditions. 

If you’re unsure whether your headlights are working properly, book a free vehicle check at your local Kwik Fit centre. 

Our expert technicians can test, replace, or realign your bulbs to restore full visibility and ensure your car is ready for any journey, day or night.