Warning of a speed trap

Freedom of Information (FOI) Act request ref: 01/FIN/25/003302/Q

Version Date: 24/06/2025

The Alliance Operations Department has provided the following information.

1) Is warning people of a temporary speed trap a crime, e.g. motioning to slow down or flashing lights?

Please note, Dorest Road Safe (DRS) is unable to provide legal advice, please seek independent legal advice for a specific case.

The warning of other drivers may constitute an offence obstructing a Police Officer.

Obstructing a police officer means preventing a police officer carrying out his duties, or making it more difficult to do so. It must be a wilful act, meaning it was a deliberate act with the rider knowing and intending that the act will hinder the officer.

The Crown Prosecution Service (CPS) charging standards actually state, among a list of behaviour, that warning other motorists of a police speed trap ahead would fulfil the offence. It doesn’t mention flashing headlights or waving at people, it just states warning other motorists.

Section 46 of The Police Reform Act 2002 made it an offence to wilfully obstruct a designated person in the execution of their duty. The civilian member of staff inside the camera van will – or should have – been made a designated person by the Chief Constable of a police area for them to carry out speed enforcement. Even if carrying out speed enforcement is their only power, if someone obstructs them then the offence is complete.

Obstructing a Police Officer is a summary only offence, making it punishable by up to one month in prison and/or a Level 3 fine, which at the time of writing is up to £1,000.

Full details of the offence - Obstructing a Police Officer, Section 89(2) of the Police Act 1996 can be found on the CPS website: Public Justice Offences | The Crown Prosecution Service

2) If it is a crime, how many prosecutions are taken against people for doing so in the last significant period of time, e.g. 5 or 10 years?

No information held. The police will charge and arrest, procesutions are the responsibility of His Majesty’s Courts and Tribunal Service (HMCTS): HM Courts & Tribunals Service - GOV.UK

3) if it is a crime, how do navigation apps such as Google Maps escape prosecution?

No recorded information held.

We understand that apps such as Google maps only show fixed position cameras and do not indicate whether any camera is or is not active.