One of the questions in your driving theory test is: “When should you flash your headlights?”
Like all theory test questions, there’s a clear answer to this, and it’s not up for debate.
When Should You Flash Your Headlights?
You should only flash your headlights to let other drivers know you’re there. This is rule 110 of the Highway Code. The rule states: Only flash your headlights to let other road users know that you are there. Do not use your headlights to convey any other message, or to intimidate other road users.
Why Do People Flash Their Headlights?
Despite the official guidance, people flash their headlights for several reasons. Maybe you’ve seen people flash their headlights to thank another driver for letting them pass. Or perhaps you’ve seen cars flash their lights to let drivers waiting at junctions know that they can pull out, or to let pedestrians know that it’s safe to cross.
This sort of thing happens on the road every day. And while it’s not technically illegal to signal to other drivers in this way, it can be actively dangerous.
Can Flashing Your Headlights Be Dangerous?
Flashing your headlights for reasons other than to let other road users know you’re there can cause dangerous situations.
For example, picture a car waiting at a busy junction. A driver notices them waiting, slows down, and flashes their headlights, to let them know it’s safe to come out. It’s a friendly gesture. But the problem is, to the waiting driver, these flashing headlights might come across as an order. They might suddenly feel pressured to pull out into the road as soon as possible. And in doing so, they may miss some oncoming traffic from the other direction – particularly if it’s a road user that’s harder to spot, like a cyclist.
Psychologically, flashing headlights seem to make us act impulsively. We seem to react to them immediately and without thinking. That’s why the highway code recommends you use them to alert other drivers to your presence. It gets their attention! But using them to signal to other drivers may make other drivers take unnecessary risks.
If you want to thank other drivers, just briefly raise your hand. And if you want to let waiting vehicles into traffic, don’t flash your headlights. Instead, slow down and leave enough of a gap for them to join. If they don’t pull into your lane, so be it. They can wait for the next gap in the traffic. Better this, than to signal to them and risk an accident.
Is It Illegal to Flash Your Headlights at Other Drivers?
Most of the time, it’s all to do with context. So long as it doesn’t cause any accidents, you probably won’t get into trouble for flashing your headlights at other road users to thank them, or to let them know it’s safe to proceed. This behaviour goes against the Highway Code, but there are no explicit laws forbidding it.
But there are at least two occasions when it’s definitely illegal to flash your headlights at other drivers:
- To warn other drivers of a police speed trap. If you’re caught flashing your headlights at other drivers to let them know there’s a speed trap ahead, you could face a fine of up to £1,000. This is a breach of section 89 of the Police Act 1997: Obstructing a constable in the execution of their duty.
- To intimidate other drivers. This is a much more serious offence, and one that could actually land you in court. The charge could be dangerous driving, which can result in 3 to 11 penalty points on your licence. Or it could be furious driving, which can result in 3 to 9 penalty points and a fine of up to £5,000.
Don’t Take Any Risks
It’s never a good idea to ignore the Highway Code. To avoid causing any accidents, only ever flash your headlights to let other drivers know you’re there. And never use your headlights in a way that’s actually against the law. Penalty points could cause you to lose your licence, and they could also affect your car insurance. Head here for more information about declaring points on your licence.