Police show exactly where they stand on flashing lights to warn other drivers

Police show exactly where they stand on flashing lights to warn other drivers The Highway Code, police and even the courts are clear where they stand on drivers who flash their headlights to warn others of a speed camera up ahead. Share Article Share Article Facebook X LinkedIn Reddit Bluesky Email Copy Link Link copied Add us as preferred source Comments By Steffan Rhys 06:29, Fri, Nov 6, 2026 Police have shown clearly how they view people flashing their headlights to warn other drivers (Image: Getty) Chances are you've found yourself in a situation where an approaching driver has suddenly flashed their headlights at you.

Instinctively, you understand what it means: there is most likely a speed camera, van or some other police presence just ahead. You might feel your fellow motorist has done you a favour by issuing the warning. In reality, they have placed themselves at risk of prosecution and a fine of £1,000. This is no theoretical risk either — drivers have genuinely faced prosecution for flashing their lights to alert others, reports Wales Online . Article continues below ADVERTISEMENT What does the Highway Code say about flashing lights?

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You can unsubscribe at any time. More Info . Highway Code Rule 110 states: "Only flash your headlights to let other road users know that you are there. Do not flash your headlights to convey any other message or intimidate other road users." Notably, Rule 112 of the Highway Code also cautions that your horn should be used "only while your vehicle is moving and you need to warn other road users of your presence" and adds: "Never sound your horn aggressively."

Is there a law against flashing your headlights? There is no specific criminal offence of "flashing headlights to warn others". However, police in England and Wales would prosecute this under Section 89 of the Police Act 1996 , which makes it an offence to "wilfully obstruct a constable in the execution of his duty." Article continues below ADVERTISEMENT Because officers are actively trying to catch speeding motorists, warning drivers so they temporarily slow down is legally interpreted as interfering with police duties.

The maximum penalty for this offence is one month's imprisonment or a £1,000 fine. In accordance with sentencing guidelines, punishments can vary from a fine and a custodial sentence through to a conditional discharge or community order. Article continues below ADVERTISEMENT It is worth noting that police treat this matter very seriously. A prime example of this emerged, perhaps surprisingly, in the weekly newsletter of a local primary school earlier in 2026.

The school cautioned that "several people are warning other motorists" about the presence of a Cheshire Police speed van that had recently been deployed to monitor traffic speeds outside the school. The school noted that officers were warning that this behaviour breached both Highway Code Rule 110 and Section 89 of the Police Act 1996, and that they "could charge anyone who appears to be obstructing their ability to conduct speed checks on other motorists by warning them", adding: "The maximum fine for obstructing a police officer is a penalty of £1,000."

Furthermore, the Crown Prosecution Service (CPS), in its official guidance on Public Justice Offences, lists "giving a warning to other motorists of a police speed trap ahead" as an example of conduct that would constitute resisting or wilfully obstructing a constable in the execution of their duty. Trending The court case: DPP v Glendinning In this 2005 case, a lorry driver was observed flashing his headlights at oncoming motorists after noticing a speed camera van on a dual carriageway.

Officers witnessed this behaviour, concluded he was deliberately alerting other drivers, and charged him with obstructing police. A lorry driver was taken to court for flashing drivers in what police said was a warning to other drivers of a speed camera in the road ahead (Image: Getty) The driver was initially found guilty, however the conviction was subsequently overturned at the High Court, where judges ruled that concrete evidence of actual obstruction was required, rather than merely the potential for it to occur.

In this particular instance, the High Court determined there was no proof that approaching vehicles were exceeding the speed limit, that motorists had altered their behaviour in response to being flashed, or that police enforcement operations had been genuinely disrupted. Nevertheless, this prosecution makes it abundantly clear that police are prepared to take motorists to court for flashing their headlights to alert others to speed cameras ahead.

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