Advanced driver-assistance systems in modern electric and hybrid vehicles are facing intense scrutiny after numerous reports of dangerously misreading speed limits, including instructing motorists to travel at 80mph in 30mph zones outside schools.
Widespread System Failures and Driver Complaints
The issue centres on Traffic Sign Recognition (TSR) technology, which uses special cameras to read road signs and provides drivers with audio and visual cues about the current speed limit. However, online owner forums for premium models like the £55,000 Mazda CX-60 and the £37,000 Volvo XC40 are flooded with complaints.
Drivers report the systems are displaying non-existent UK speed limits, such as 80mph, 90mph, and even 100mph. One driver recounted being told he could do 80mph in a Sainsbury’s car park, while another described the ‘mayhem’ it causes around school zones. A third owner provided a chilling account: ‘So far it has read ten as 70, 19 as 90 and 30 as 80. It’s really dangerous.’
When the Car Takes Control: The Cruise Control Danger
The problem is compounded in vehicles where the TSR system is linked to self-adapting cruise control. In these cases, the car can automatically accelerate or brake to match an incorrectly identified speed limit. This poses a severe risk, particularly in high-performance models like the £96,000 Porsche Macan Turbo, which can accelerate from 0-60mph in a mere 3.3 seconds.
Helen, a Porsche Macan owner, shared a frightening experience online. ‘The car abruptly changed from 70mph to 5mph when it incorrectly read a 50mph sign,’ she wrote. ‘Thankfully nothing fast or heavy was behind me and I could quickly take over driving.’ Many, like her, have been forced to deactivate the function entirely.
Richard Wright, a 45-year-old Mazda CX-60 owner from Tunbridge Wells, Kent, explained how the distracting alerts on the windscreen’s heads-up display have caused him to hit the brakes unnecessarily. ‘When it’s constantly flashing up warnings that you should be doing 80mph in a 30mph... it’s extremely distracting,’ he told the Mail.
Manufacturer Responses and an Ongoing Issue
The faults appear to have been ongoing for over a year, with dealers reportedly continuing to sell the vehicles without warning customers. The technology, which blends camera and GPS data, has proven unreliable, sometimes misreading stickers on lorries or signs on side roads. Volkswagen has already decided against installing the feature in cars sold in Australia, labelling it as ‘rushed to market’ by rivals.
Following an inquiry by the Mail, Mazda UK confirmed it is investigating the issue, reiterating that drivers remain ultimately responsible for monitoring road conditions. Porsche stated it is developing a fix and will soon offer a free software update for Macan owners to optimise the TSR technology, while also noting that dirty or unclear road signs can disrupt the system.
