As we reported on Monday, National Highways has identified a technical anomaly that has impacted how its Highways Agency Digital Enforcement and Compliance System (HADECS) cameras interact with variable speed limit signs on a limited number of A-roads and motorways.

The anomaly has meant there was, at times, a slight delay between cameras and variable speed signs, leading to some drivers being incorrectly detected as speeding after the limit had changed. This has resulted in a number of people incorrectly facing enforcement action for speeding.

The technical anomaly impacts 154 HADECS cameras deployed on 10% of the strategic road network (SRN). As a result, National Highways has identified that there have been approximately 2,650 total erroneous activations on impacted roads since 2021, which is fewer than 0.1% of activations during this time period and which is the equivalent of fewer than 2 a day. Not all activations are enforced, so the numbers impacted will be lower than this. National Highways is continuing its investigations back to 2019, when the upgrade of cameras began, to ensure that everyone who has been impacted is identified.

In October National Highways’ executive instructed their camera supplier 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 this issue has now been agreed and National Highways is working with the police to allow them to implement this solution as a priority.

In the written ministerial statement of 16 December 2025, Department for Transport (DfT) ministers committed to conduct ‘an independent investigation into how this technical anomaly came about, to ensure that lessons can be learnt’. The Secretary of State for Transport has appointed Tracey Westall OBE, Non-Executive Director of DfT, to be the lead reviewer for this independent review.

The review 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
• understand the process through which this issue was escalated within National Highways to the executive and board and when key stakeholders were informed
• review and assess the response, accountabilities and governance processes National Highways apply to technical and operational issues, including the HADECS technical anomaly, including the roles of the Board and executive
• where appropriate, 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 review is not for the purposes of determining liability, apportioning blame or disciplinary action against any individual.

Confidential or sensitive information (including, in particular, names, addresses or other information relating to an individual (with the exception of their job title/job description)) provided for the purpose of the review shall only be shared or made public to the extent that it is necessary to fulfil these terms of reference. Privileged information, if provided for the purposes of the review, shall not be shared or made public.

The scope of the review is limited to consideration of the following:

• the circumstances through which technical and operational issues, including, but not limited to, the HADECS technical anomaly, are identified and how and when they are escalated within National Highways to the executive and board
• the response of National Highways’ executive and board to technical and operational issues, including but not limited to, the HADECS technical anomaly
• processes followed by National Highways’ executive and board when assuring the work of suppliers when developing, testing and implementing the HADECS cameras and other new technology on the SRN, including contract management, assurances sought from suppliers and accountabilities
• National Highways’ decision-making processes, governance and relationship with relevant supplier(s) – this includes National Highways’ approach to applying lessons learned from previous responses to technological and operational issues

(Picture: Yay Images)