Flashing signs which can detect when people are using a mobile phone inside a car has been trialled in Brighton and Hove to warn drivers to keep their eyes on the road.
One has already been placed in the city, and the council is hoping to get it starting again next month.
The signs have been funded by the Sussex Safer Roads Partnership (SSRP), which hopes to persuade people not to break the law by driving and using a phone.
A spokesman for Brighton and Hove City Council said: “The mobile sign detects when someone is on the phone when driving and shows a display to remind drivers not to use hand-held mobiles while driving.
“It does not store images or data and is simply a warning/reminder and is a valuable road safety tool, much like the speed sensors that also remind people to keep to the limits.
“The signs are not operating at the moment but we are hoping to resume in November.”
The sign, developed by a local company called Thermotor, will be rolled out across Sussex if the trial proves a success.
A spokesman for SSRP said: “It is important to stress that this campaign is entirely educational. The idea is to alert drivers to the law, and spark behavioural change, instead of issuing fines and points.”