Britain’s vehicle safety and security authority reports problems with speed limiter technology fitted to all new cars, saying the systems can fail to recognise when the legal speed limit changes. In testing carried out on UK roads, the regulator found “serious inaccuracies,” with the speed limiter not consistently identifying updated limits. The findings indicate that in a significant share of cases the system either does not respond to a new limit or does so incorrectly. One in four instances are cited as showing failures to identify changes in legal limits. The report points to performance gaps in how the systems interpret limit updates in real-world driving conditions, rather than purely controlled settings. The authority’s testing therefore raises concerns about reliability and compliance for drivers who rely on these systems to manage speed when roads change. The regulator’s results focus on the accuracy of limit recognition and the ability of the technology to track legal changes while vehicles are in use on public roads.