Flashing headlights

Headlights flashing: What does it mean?

Last updated April 21, 2023

Flashing headlights are a common sight on the roads, with drivers often flashing their main beam headlights as a way of communicating with other drivers, cyclists and pedestrians.

So, what does this commonly used signal mean? Is it a warning sign, a friendly gesture or a form of road rage?

As a safe and responsible driver, it is important that you are familiar with how to use your headlights (and other light systems, such as the hazard warning and parking lights) correctly.

In this guide, we will clarify the meaning of flashing headlights, when it is legal to flash your headlights in the UK – and when doing so could land you in trouble with the law.

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What does it mean if somebody flashes their headlights at you?

Flashing headlights are often interpreted to mean different things depending on the context and who a driver is attempting to communicate with (e.g. another driver, a pedestrian or a cyclist).

Common uses for flashing headlights include:

  • Warning another driver about a potential hazard ahead.
  • A driver’s signal to a pedestrian or cyclist that they will wait until they have crossed the road safely before continuing driving.

When should you flash your headlights?

According to the Highway Code, you should only ever flash your headlights to warn other drivers, pedestrians and cyclists of your presence on the road. This is the only scenario where you are legally permitted to flash your headlights.

Is it illegal to flash your headlights in the UK?

Whilst many drivers have flashed their headlights for reasons other than simply warning other road users of their presence, if you do this, you risk getting in trouble with the police.

For example, if you are found to have flashed your headlights to warn other drivers of an upcoming speed camera, you may be fined up to £1,000.

Flashing your headlights on your driving test

You should not flash your headlights on your driving test, as this could create a potential hazard for other road users. During your driving test, you are unlikely to be placed in a situation where you would be required to flash your headlights.

Aggressive headlight flashing (with examples)

Here are several scenarios in which you may witness ‘aggressive’ headlight flashing from other drivers. As a law-abiding driver, you should never use your headlights in the manners highlighted below:

  • Tailgating

    Some drivers might flash their headlights to the driver immediately in front of them to tell them to speed up.

  • Road rage

    Drivers are sometimes known to flash their headlights to express anger or annoyance with another driver instead of sounding their horn (another gesture which should only be used to warn other road users of your presence).

  • Intimidating other road users

    You may encounter drivers who flash their headlights at other road users to intimidate them into changing lanes or allowing them to overtake. This sort of behaviour can lead to potentially dangerous situations, especially on roads in built-up areas.

Courteous headlight flashing (with examples)

Drivers might flash their headlights to convey a friendly message, too. There are several scenarios in which you may encounter this, although you should not flash your headlights when you find yourself in similar situations.

  • Greeting drivers or pedestrians

    You may spot drivers flashing their headlights to greet other drivers or pedestrians that they recognise whilst driving.

  • Hazard ahead

    Although you should use your hazard lights to warn road users of upcoming hazards, briefly flashing your headlights is a quicker and more accessible way to alert them if you need to do so right away.

  • Giving way to another driver or pedestrian

    Perhaps the most common reason that drivers flash their headlights is to give way to other road users (e.g. stopping to let pedestrians cross the road or pulling over to allow an oncoming driver to pass).

  • Warning road users of speed cameras

    Some drivers might flash their headlights at other road users to warn them of a ‘speed trap’, speed camera or traffic light camera up ahead. You should not do this – any driver found to be warning other road users of upcoming speed cameras could be fined up to £1,000.

  • Telling drivers they haven’t put their headlights on

    Drivers sometimes flash their headlights to alert other drivers that they should have their headlights on.

  • Another driver has left their boot open

    A driver may flash their headlights to warn you that your boot is open.

  • Warning a driver about their vehicle

    Drivers will sometimes flash their headlights to alert a fellow driver that something is wrong with their car, such as a broken light or flat tyre.

What if somebody flashes their headlights behind me?

If a driver behind you flashes their headlights, they are probably telling you to speed up, move over - or want to get your attention for another reason.

You are most likely to encounter this behaviour on the motorway (or on a road with a lower speed limit, where other drivers may pressure you to meet or exceed the limit).

If a driver flashes their headlights for any of the above reasons, it’s best not to rise to it. You could potentially contribute to a dangerous situation - or at a minimum, distract yourself from driving.

How to flash your headlights

In most vehicles, you can flash the headlights by quickly and repeatedly pulling the indicator stalk towards you. This will turn your high beams on and off.

Frequently Asked Questions

Lorry drivers sometimes flash overtaking vehicles (often other lorries) to let them know that they have passed them safely.

It’s difficult for lorry drivers to gauge the end of their load from the perspective of other lorry drivers. Therefore, they often flash their headlights as a sign of courtesy - and for the other driver’s peace of mind.

Headlights being flashed twice is generally interpreted to mean ‘go’ and is a gesture often used by drivers giving way to other road users.

Three headlight flashes can be interpreted as an alert or warning, whilst five or more headlight flashes has no set meaning (but is generally a sign that the other driver is determined to get your attention).

No. It is a common misconception that flashing your headlights at stoplights (specifically temporary stoplights used around roadworks) will make red lights turn green.

Some people have reported that this works, but this is likely just confirmation bias. In reality, this would be an unsafe way for traffic lights to work.