As yet, the technology is unable to detect whether the driver is using the phone, but the authorities hope that it will serve as a way of deterring people from using their phones while driving their vehicles.
Chris Spinks, of Westcotec, the firm behind the cutting-edge technology, explained to the BBC: "So many people, by force of habit, can't resist using their phone.
"It's a huge problem on our roads and drivers know there is no remote detection system.
"The system cannot differentiate between a driver and the passengers on a bus, for example, but this goes some way towards remotely warning drivers that they can be detected using their phone.
"Hopefully, as time goes on it will become as socially unacceptable as drink driving."
The technology, which is being trialled in Norfolk, detects the phone signal inside the vehicle and it triggers a roadside warning sign of a mobile that features a red line through it.
Inspector Jonathan Chapman, of Norfolk Roads Policing unit, has welcomed the trial.
He said: "Any scheme which prevents this kind of behaviour is welcomed.
"Using a mobile phone at the wheel is one of the fatal four road offences which can have devastating consequences if it causes a fatal or serious collision."