Drivers have been warned they face a £1,000 fine should they share the location of mobile speed cameras on social media.
Anyone who posts the location a police speed trap could be in breach of section 89 of the Police Act 1997.
This was designed to stop people obstructing a constable in the execution of his or her duty.
Anyone breaking this law also faces a jail term of one month.
This was highlighted by a driver in Wales who took a picture of the mobile unit near Abersoch, and was immediately advised to take it down.
Mobile speed camera
PA
A spokesman for the North Wales Police road policing unit said: “Publicising the locations of speed traps hampers the good work that staff and officers do to reduce speeding motorists, which is one of the “Fatal Five” offences.
"Motorists could be prosecuted if they are caught warning other drivers on the road for any speed trap.”
As well as speed cameras, Transport Secretary Grant Shapps declared he wants to “banish the boy racer” as he announced plans to deploy noise cameras to catch “rowdy drivers”.
Transport Secretary Grant Shapps arriving in Downing Street, London for a Cabinet meeting
Stefan Rousseau
His department has invited MPs to enter a competition to find the noisiest streets in England and Wales amid concerns about the impact on residents from motorists revving engines and using illegal exhausts.
Four areas will be chosen to take part in a £300,000 trial of innovative noise cameras.
Police have the power to fine drivers who flout noise rules, but struggle to gather evidence.
The cameras can automatically detect when vehicles are breaking legal noise requirements.
They will be able to provide real-time reports to police, which could result in more targeted enforcement.
Preliminary testing showed the technology can identify individual vehicles in certain circumstances and assign noise levels to them.
Mr Shapps said: “We want those in Britain’s noisiest streets, who are kept up at night by unbearable revving engines and noisy exhausts, to come forward with the help of volunteer areas to test and perfect the latest innovative technology.
“For too long, rowdy drivers have been able to get away with disturbing our communities with illegal noisy vehicles.
“It’s time we clamp down on this nuisance, banish the boy racer and restore peace and quiet to local streets.”
