Experts Call for New Rules Surrounding Intelligent Speed Assist Systems in Vehicles

Road safety experts are calling for significant changes to the way Intelligent Speed Assist (ISA) systems are tested and approved after new research revealed that some vehicles are incorrectly identifying speed limits far more often than current regulations suggest. The findings have reignited concerns about driver confidence in Advanced Driver Assistance Systems (ADAS) and whether existing approval standards are rigorous enough for real-world driving.

ISA technology became mandatory on many newly approved vehicles in Europe from 2024 as part of wider road safety legislation. Designed to help motorists stay within legal speed limits, the system uses a combination of traffic sign recognition cameras, GPS data and digital mapping to detect the current speed limit and warn drivers if they exceed it. In some vehicles, the technology can also limit acceleration, although drivers can typically override the intervention when necessary.

New Testing Raises Concerns

Recent testing by vehicle safety specialists has highlighted shortcomings in the way ISA systems are currently assessed. Existing regulations require vehicles to achieve at least 90% accuracy over a prescribed driving distance of around 250 miles. However, critics argue this method can mask errors that occur during individual speed limit changes, which are often the moments that matter most.

Using a more detailed event-based assessment, researchers found that one vehicle correctly identified speed limit changes only around 74% of the time, meaning it displayed the wrong speed limit in approximately one out of every four transitions. Even one of the best-performing vehicles tested still failed to correctly recognise around one in ten speed limit changes.

Why Accuracy Matters

While ISA systems are designed as driver assistance rather than autonomous control, motorists remain legally responsible for obeying speed limits. If the system displays an incorrect speed limit, it could create confusion, particularly in unfamiliar areas or where limits change frequently.

Safety experts warn that repeated inaccuracies could reduce driver trust in the technology, leading many motorists to disable the feature altogether. This would undermine one of the key objectives of introducing ISA, which is to reduce speeding and improve road safety.

There are also concerns that incorrect speed information could increase the risk of drivers unintentionally exceeding legal limits, potentially resulting in penalties or contributing to road traffic collisions.

Calls for Stricter Regulations

Industry experts are now urging regulators to introduce updated approval standards that better reflect real-world driving conditions. Rather than measuring overall accuracy across long journeys, they believe systems should be assessed on how reliably they detect every individual speed limit change.

Improved testing could encourage manufacturers to enhance traffic sign recognition software, GPS mapping accuracy and sensor performance before vehicles receive approval for sale.

Many believe that higher testing standards would ultimately increase consumer confidence in ADAS technologies while ensuring safety systems perform consistently across different road environments.

Intelligent Speed Assist Is Here to Stay

Despite the concerns, road safety organisations continue to support Intelligent Speed Assist as an important technology capable of reducing speeding-related collisions and saving lives. The issue, experts say, is not the concept itself but ensuring that the systems are reliable enough for everyday driving.

As vehicles become increasingly reliant on advanced driver assistance features, the accuracy and consistency of technologies such as ISA will become even more important. With governments continuing to consider wider adoption of mandatory safety technologies, the latest findings are likely to play a key role in shaping future regulations and testing procedures.