An independent investigation into a technical fault on National Highways variable speed cameras, which resulted in thousands of drivers being fined incorrectly, has been launched by the Department for Transport (DfT).
National Highways revealed in December that it had found a fault on variable speed cameras on some A roads and motorways.
The technical issue had impacted 154 cameras deployed on 10% of the strategic road network (SRN).
The issue dated back to 2021 and involved a 10-second delay between cameras and variable speed signs, leading to some drivers being incorrectly detected as speeding after the limit had changed.
National Highways identified around 2,650 drivers who may have been impacted by the fault.
Launching the independent review into the speed camera fault, the DfT revealed that National Highways had instructed its camera supplier on October 17, 2025, to pause the transfer of variable speed data to police forces in order to ensure no further individuals were incorrectly prosecuted.
A Home Office-approved solution to the fault has now been agreed and National Highways is working with the police to allow them to implement this solution as a priority.
Tracey Westall, non-executive director at DfT, has been appointed to be the lead reviewer for the independent review.
The DfT says that it will seek to establish the cause of the technical anomaly, the process by which it was identified, and if there were any missed opportunities to identify it sooner or prevent it from occurring in the first place.
It also aims to understand the process through which this issue was escalated within National Highways to the executive and board, and when key stakeholders were informed.
Furthermore, it will review and assess the response, accountabilities and governance processes National Highways apply to technical and operational issues.
Where appropriate, the review will make recommendations for any changes that could be made to National Highways’ governance, accountabilities or processes (including those of relevant suppliers) that would reduce the risk of similar issues arising in the future or improve how such issues are managed.
The DfT stressed that the review is not for the purposes of “determining liability, apportioning blame or disciplinary action against any individual”.
A final report is expected in 18 weeks.
When the story first broke, National Highways apologised to anyone affected and said that they will be reimbursed and have points removed from their licence where relevant.
