As more automakers develop automated driving systems that allow drivers to take their hands off the steering wheels for short periods of time, a new report says General Motors has developed the best system.
Consumer Reports tested four of the most popular systems and says Cadillac's Super Cruise does the best job of ensuring the vehicle is driven safely while making sure drivers pay attention when they take their hands off the steering wheels.
"Super Cruise has a camera that looks at the drivers' eyes and warns them if they look away for too long or fall asleep, and that's a game changer," said Jake Fisher, director of auto testing at Consumer Reports.
"This is definitely a shot across the bow of Tesla, which already has Autopilot," said Michelle Krebs, analyst for AutoTrader said.
Consumer Reports ranks Tesla's Autopilot as the second-most effective automated driving system, criticizing it for not doing enough to keep the driver engaged when the vehicle is in Autopilot mode.
"Autopilot is a strong system, but it doesn't have enough safeguards," said Fisher.
Consumer Reports rated Nissan's ProPILOT Assist as the third-best system and Volvo's Pilot Assist as the least effective of the four it tested. Nissan says ProPILOT Assist is a "hands-on" driver-assist system rather than a "self-driving" feature. Volvo echoed that response.
"Pilot Assist is not an autonomous driving system. It is a driver assistance system designed to keep the driver in the loop at all times with hands on the wheel, eyes on the road and the mind on driving," said Johan Larsson, a Volvo spokesman.
The systems were evaluated at Consumer Reports' test track and on public and highways. The reviews are based on five criteria: capability and performance, ease of use, if the systems made it clear when it was safe to use, whether they kept the driver engaged, and how they alerted or handled an unresponsive driver.
Consumer Reports is not warning people to avoid using any of the automated driving systems it tested, but it wants drivers to better understand the limits of the technology.
Ever since Tesla unveiled Autopilot in 2015, it's been controversial technology. When it first came out in "beta" mode, Tesla CEO Elon Musk said, "It is important to exercise great caution at this early stage."
Not everyone got the message. Within months of rolling out, Tesla owners posted videos on YouTube showing themselves driving hands free and not always paying attention.
In 2016, a Tesla driver was killed when his Model S in Autopilot mode crashed into a semi-truck in Williston, Florida. The National Transportation Safety Board concluded limitations in Tesla's Autopilot system played a major role in the crash. NTSB Chairman Robert Sumwalt bluntly summarized the case saying, "System safeguards were lacking."
Two years later, as more vehicles and more automakers develop automated driving systems, Consumer Reports is worried drivers will become too complacent and not be ready to grab the steering wheel if their car or truck steers itself into trouble.
"The big concern is putting too much trust in these systems," said Fisher of Consumer Reports. "Drivers are not always paying attention when these systems are in use."
WATCH: GM demonstrates its hands-free 'Super Cruise' system
