Systems of some cars designed to keep drivers alert fail, according to a study by the US AAA.

Some vehicles equipped with automated assistance technology intended to keep drivers alert and aware of the road fail at that task, according to a study by the American Automobile Association (AAA).

The study indicates that surveillance systems based solely on the way drivers handle the wheel are not successful. Those that use cameras to monitor drivers’ head and eye positions were much more effective at keeping drivers’ attention when the vehicle’s software is activated.

On average, these direct control systems alerted the driver about 50 seconds earlier than those based on indirect feedback from the steering wheel, according to AAA.

Surveillance systems are becoming more widespread as part of advanced driver assistance systems (ADAS), which can automate some driving tasks and control a car’s braking and acceleration. Manufacturers are offering them in more and more models, and the cost of the technology drives up vehicle sales prices.

Carmakers tout these systems as a safety and comfort enhancement, but insurers and safety researchers have repeatedly warned that drivers can mistake them for self-driving systems, leading to overconfidence.

The AAA study tested two camera-based surveillance systems, a 2021 Cadillac Escalade with the system “Super Cruise” from General Motors and a 2021 Subaru Forester with technology “EyeSight”, and two systems that only rely on steering input: a 2021 Hyundai Santa Fe with “Highway Driving Assist” and a 2020 Tesla Model 3 with “Autopilot”.

Hyundai’s system was the worst performer, followed by Tesla. Subaru and GM’s systems were much better at keeping drivers engaged, but neither system was a perfect performer.

“Driver monitoring systems are a good first step in preventing fatal crashes, but they are not foolproofsaid Greg Brannon, AAA’s director of automotive engineering.