Is it illegal to warn of a speed trap

After I saw a police motorcycle parked up by the road I flashed some other bikers as I drove away. I don’t think they were speeding but I was then followed by another police motorcyclist. He stopped me and gave me a fixed penalty notice saying I had broken the law. I have searched the Highway Code but cannot find anything about using headlights to warn other drivers as being wrong. Can you confirm if he was right to fine me?
FazerGuy, by email


There is an offence of warning others about a speed trap.

  1. Warning the driver of a motor vehicle who is driving in excess of the speed limit that there is a speed trap amounts to obstructing a constable in the execution of his duty contrary to s.89(2) of the Police Act 1996: based on the case of Bastable –v- Little from 1907
  1. Betts –v- Stevens from 1910 – this confirmed that there must be some act of warning and there must be evidence that the driver was breaking the law.

The policeman probably had in mind the case of Bastable when he gave you the fine but he may not have acted in accordance with the law as you have not mentioned that there was actually a mobile speed camera. If you have not yet paid the fine I would seek clarification from the police that they have complied with the law. If they realise that they have not done so, they may cancel the ticket.


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