What Car?

Autonomous or not? The shortcomin­gs of active safety systems

Many people think they can buy a car that can drive itself, but independen­t tests of ‘autonomous’ systems show that they can’t always be relied upon to prevent accidents

- Photograph­y: John Bradshaw Claire Evans Claire.evans@haymarket.com

A SURVEY CARRIED out by car security and safety organisati­on Thatcham Research and crash testing outfit Euro NCAP has revealed that 71% of drivers globally believe some current cars can drive themselves and, because of this, 10% would be tempted to take a nap while using a motorway assistance system such as adaptive cruise control.

However, the first independen­t test of advanced driver assistance systems (ADAS) demonstrat­es why drivers shouldn’t leave the driving to their cars.

Thatcham put 10 of the latest models, all equipped with ADAS, through a series of tests. The cars were the Audi A6, BMW 5 Series, DS 7 Crossback, Ford Focus, Hyundai Nexo, Mercedes-benz C-class, Nissan Leaf, Tesla Model S, Toyota Corolla and Volvo V60. The tests included assessing how each car reacted when driven at more than 40mph towards a stationary vehicle and when driven towards and then around a large pothole that would be visible to the driver but not to the ADAS.

What Car? was given the opportunit­y to watch demonstrat­ions of some of the cars undergoing these two tests, in which three of the cars fitted with similar-sounding systems reacted very differentl­y. The V60’s automatic emergency braking (AEB) system activated and brought the car to an emergency stop a few inches behind the stationary vehicle. Tesla’s adaptive cruise control (ACC) spotted the stationary car and gradually slowed the Model S to a halt just behind it. The Leaf’s ACC failed to react, because it won’t stop the car at speeds above 37mph, and its AEB, which should give support at speeds up to 56mph, followed suit, so the Leaf rear-ended the car.

These results highlight the complexity of the different systems on cars and the need for drivers to understand their capabiliti­es and shortcomin­gs. Nissan stated in response

to the Leaf’s performanc­e: “This was a media demonstrat­ion conducted by Thatcham and not an official test. They have not shared their findings or given us access to the vehicle tested, so we are unable to verify the result.

“Official safety system testing carried out by Euro NCAP concluded that the driver assistance technologi­es on the Leaf perform as designed in a variety of scenarios. The Leaf also has a five-star safety rating from Euro NCAP.”

In response to its 7 Crossback’s similarly poor results, DS said: “The 7 Crossback has an emergency braking system equipped to detect vehicles (moving or stationary) or pedestrian­s on the road. It’s designed for urban situations and operates between 3mph and 52.8mph, with the ability to trigger the brakes automatica­lly to avoid or minimise the outcomes of impact.”

In contrast, Thatcham believes the ACC of the Model S engages too early, and that could result in drivers becoming over-reliant upon it. In the pothole test, which assesses the cars’ lanekeepin­g assistance, all the systems cut out to allow the driver to swerve and then reactivate­d, apart from Tesla’s, which tried to keep the car in the centre of the lane and made it difficult for the driver to steer around the pothole.

The fact that the Tesla system tried to stop the driver from deviating from the correct lane position could make some drivers feel like the car is more in control than they are, and that again could lead to over-reliance.

Matthew Avery, director of research at Thatcham, said: “These new Euro NCAP assessment­s are a heads-up for drivers on what these systems can and can’t do and starkly show their limitation­s, proving beyond any doubt that they are not autonomous.

“It’s a delicate balancing act. Offer too much assistance to the driver and they disengage; offer too little and the driver thinks ‘What’s the point?’ and switches the system off. The best systems are those that support the driver but leave them in no doubt that they’re in control.”

Mike Hawes, chief executive of the Society of Motor Manufactur­ers and Traders, added: “Safety is the top priority for car makers, which spend billions developing technology that mitigates driver error, reduces accidents and saves lives. Many new cars are now available with advanced assistance systems, where the driver must remain in control at all times. Such systems are already making our roads safer and are expected to save 2500 lives by 2030.

“The industry is working with regulators in the UK and at United Nations level to determine what makes a vehicle fully autonomous. This will ensure a common understand­ing and that all autonomous cars meet exacting internatio­nal standards.”

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 ??  ?? The Leaf didn’t react as it approached a stationary car
The Leaf didn’t react as it approached a stationary car
 ??  ?? You must always keep a hand on the wheel
You must always keep a hand on the wheel

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