Intelligent cat's eyes are being used on a section of Scotland's busiest motorway.
The studs can help safety while driving in the dark
The Intelligent Road Stud has been installed on the M8 at junction six, Newhouse, Lanarkshire.
The Scottish Executive said the flashing studs were designed to improve road safety and were more visible than conventional cat's eyes.
The studs can also sense fog, rain and ice and help steer motorists through difficult weather conditions.
The information is collated by the National Driver Information and Control System (Nadics), which offers information on Scotland's roads network.
An executive spokeswoman said: "This trial is aimed at improving safety by detecting slow and queuing traffic.
"Flashing studs in the road will warn approaching drivers about potential incidents. There are no plans to use the studs as speed cameras.
"They have the capacity to measure a car's speed but details would be used to help slow down traffic and improving road safety.
"The quality of the information recorded would not be accurate enough to be used as evidence that could prosecute individual drivers for speeding offences."
The RAC in Scotland said the new cat's eyes "sounded like Big Brother stuff".
Spokeswoman Sue Nicholson said: "They are only being trialled as far as I'm aware, so motorists should not be too worried about them because they are not going to be used for enforcement.
"Speed cameras have to be visible from a certain distance, so evidence from them would not be acceptable in court.
"However, that is not to say that might not happen at some stage in the future."