Less than a third of Scotland’s fixed speed cameras are active and catching speeding motorists, according to figures obtained by the Press Association.
The data revealed that just 50 – or 29 per cent – of the 173 cameras installed in Scotland were operational.
Police Scotland responded to the news by insisting that road safety remained a priority and that fixed cameras were part of a range of measures used to influence drivers.
While the report doesn’t identify which speed cameras are out of action, road safety groups have reacted badly to the news.
Neil Greig, director of policy and research at IAM RoadSmart, believes all fixed speed cameras should be operational.
“There's no doubt that people slow down, no matter whether there's an active camera there,” he told BBC Scotland.
“There's no way of knowing there's a camera within the housing so people do slow down, but the ultimate deterrent is knowing that if you flash that camera, you're going to get a ticket through the post in 14 days’ time.”
Mr Greig added that whenever motorists see a fixed speed camera, they should be 100 per cent certain that it is active.
Police Scotland's head of road policing chief superintendent Stewart Carle said fixed speed cameras weren’t the only way to improve road safety.
"Speed cameras have been proven to reduce injuries and road deaths in the locations where they are placed [but] they are not the sole means of influencing driver behaviour in order to keep people safe,” he told BBC Scotland.
Mr Carle added that the deployment of fixed and mobile cameras is based on collision data and speed analysis and that “a mix of both types of cameras is appropriate to positively influence driver behaviour”.
The revelation that only three in ten fixed speed cameras in Scotland work was uncovered as part of a wider report that revealed just half of fixed speed cameras on British roads are switched on.
In four regions (Northamptonshire, Cleveland, Durham and North Yorkshire), all fixed cameras had been deactivated.
Ben Robb, brand manager at Dieselink, said: “It is a postcode lottery over whether any speed cameras you see are actually working. Some motorists will take their chances and for that reason, every fixed camera should be working.”