As drivers get more familiar with and develop trust in partial automation, they fidget with electronics and take both hands off the wheel more often. As a result, their attention problems grow and their focus slips.
Those are the highlights of a new study that examined driver engagement behind the wheel of vehicles with various levels of automation and technology and underscored the need for better safety standards.
The findings were released on Thursday by the Insurance Institute for Highway Safety, a nonprofit financed by the insurance industry, based on new research conducted in conjunction with the Massachusetts Institute of Technology’s AgeLab.
For the study, researchers studied the behavior of drivers of two vehicle models to determine if there were differences between stand-alone adaptive cruise control (ACC) and the combination of ACC and lane centering.
One test vehicle (a Land Rover Range Rover Evoque) was equipped only with ACC, which automatically keeps the vehicle traveling at a speed chosen by the driver while maintaining a pre-established following distance. The other (a Volvo S90) was outfitted with a level 2 partially automated system that combines ACC with active lane keeping, a technology that keeps the vehicle positioned laterally in the travel lane.
(Levels of automation range from 0 (no automation) to 5 (fully self-driving). Level 1 systems can assist the driver with one driving task, like ACC. Level 2 systems, like Pilot Assist, which was used in the study, can assist with two tasks. Level 2 is the highest level of automation available in vehicles today.)
“Drivers were more than twice as likely to show signs of disengagement after a month of using Pilot Assist compared with the beginning of the study,” Ian Reagan, senior research scientist for the Insurance Institute and lead author of the study, said in a statement. “Compared with driving manually, they were more than 12 times as likely to take both hands off the wheel after they’d gotten used to how the lane centering worked.”
For a month, researchers studied the driving behavior of 20 volunteers as they gained familiarity with advanced driver assistance features, assessing how often they removed both hands from the steering wheel or took their attention away from the road to use their cell phone or adjust the controls on the vehicle’s console.
Initially, there was little or no difference in how frequently drivers showed signs of disengagement, whether they were driving manually, using ACC or using Pilot Assist. But after a month, drivers were substantially more likely to let their focus slip or take their hands off the wheel when using automation, and the impact was more dramatic with a level 2 system than with ACC alone.
Level 2 systems like Pilot Assist, Tesla’s Autopilot, Cadillac’s Super Cruise and Mercedes-Benz’s Intelligent Drive, are not designed to replace the driver. “They have trouble negotiating many common road features, so the driver must be in control at all times,” the Insurance Institute said. “However, with the automation managing steering and speed — quite well in some cases — it’s easy for the driver to lose focus.”
Earlier this year, the Insurance Institute issued a series of safety recommendations for partial automation systems for improving how the technology can monitor if drivers are paying attention and how it responds if drivers are disengaged. The safety group noted that the European New Car Assessment Program recently launched ratings for driver assistance technologies that assess those capabilities and how well they control vehicle speed and steering, but “ U.S. regulators have yet to develop similar ratings or standards.”
“This study supports our call for more robust ways of ensuring the driver is looking at the road and ready to take the wheel when using Level 2 systems,” Reagan added. “It shows some drivers may be getting lulled into a false sense of security over time.”
The findings of the Insurance Institute's study of “this evolving road safety threat.” Cathy Chase, president of Advocates for Highway and Auto Safety, said in a statement, underscore the need to create minimum performance safety standards to help ensure that the technology performs as expected. “Moreover, proven safety technology should be standard equipment in all new vehicles and not sold as add-ons in luxury packages together with non-safety features such as heated seats or leather interiors. Safety should be accessible to all consumers, not just those who can afford pricey upgrades or higher-end vehicles.”
For more information about the study, click here.