Thousands of drivers could have their speeding fines cancelled after a fault caused some cameras to be falsely triggered on English A roads and motorways.
National Highways said it had identified 2,650 wrongful speed camera activations since 2021 due to a delay between cameras and variable speed signs.
Affected drivers will be contacted by police and reimbursed for any fines, while points will be removed from their licences where necessary.
Not all camera activations are enforced, meaning not all wrongful activations resulted in fines.
National Highways apologised for the error.
“Safety is our number one priority,” said chief executive Nick Harris.
“All drivers should continue observing the posted speed limits as normal. Anyone who has been impacted will be contacted by the relevant police force.”
The agency said a temporary fix had been implemented, providing an extra layer of data from the cameras to police forces so they can filter out any faulty captures.
However, no clear timeline was given for when a permanent fix will be in place.
National Highways, which operates England’s motorways, blamed an “anomaly” in how variable speed cameras were interacting with signs on some A roads and motorways.
This caused a delay of around 10 seconds between cameras and relevant variable speed signs, resulting in some drivers being incorrectly identified as speeding after the limit had changed.
For example, on a road where the speed limit increases, a driver may see a sign showing 60mph, while the camera may still be working on the basis of a previous 40mph limit.
National Highways said the 2,650 incidents since 2021 represent fewer than two per day, compared with more than six million activations of speed cameras on the affected roads during the same period.
The anomaly has affected 10% of England’s motorways and major A roads.
The fault impacts 154 cameras out of 400 across the motorway network – all variable speed cameras on smart motorways, plus a section of the A14 between Huntingdon and Cambridge and the A1 approach junction to the A14.
National Highways is working with police to review activations and assured that nobody will now be wrongly prosecuted.
Meanwhile, police forces have paused issuing fines from variable cameras until they are confident in their accuracy.
A Department for Transport spokesperson said: “We apologise to anyone who has been affected. Safety was never compromised, and we are working with policing to ensure nobody is incorrectly prosecuted in future.
“Enforcement is still in place, and the public can remain confident that only motorists who break the rules will be penalised.”
