“If because of the automation, inattention goes up substantially, then the number of crashes could well go up,” cautioned Alain Kornhauser, who chairs Princeton University’s autonomous vehicle engineering program. “If the amount of inattention remains the same, then many fewer Teslas will crash due to that amount of inattention — the automation substantially reduces the probability of a crash.”
Tesla drivers will be alerted by a chime and visual alert when they need to take over, which in some cases could be immediately. While that may grab drivers’ attention, the danger is that given human nature, it won’t always be enough time for them to react to a dangerous situation. A few seconds of notice could be the difference between a safe trip and a crash.
Tesla Motors noted that its cars are equipped with an auto-braking system to intervene in the event of an imminent collision. And it believes that its new autopilot mode will increase safety.
“We’re building autopilot to give drivers more confidence behind the wheel, increase their safety on the road and make highway driving more enjoyable,” said a Tesla spokesman.
A recent Stanford University study found that a two-second warning – more time than Tesla drivers are guaranteed — was not enough time to expect drivers to be able to safely retake control of a vehicle that switches from autonomous to manual mode. The Stanford research — conducted in a lab that simulates driving — found that test subjects given five seconds of warning were able to safely retake control of the vehicle. These test subjects were only asked to monitor the car’s activities.
In another study the researchers also looked at drivers’ ability to resume control after doing a secondary task, such as watching a video. The findings were similar — a two-second buffer wasn’t enough, but most drivers managed with a five- or eight-second buffer.
“People seem to be gravitating toward somewhere in that seconds to minute range,” Nathaniel Beuse, associate administrator for vehicle safety research at NHTSA, said at a recent Volvo event. “But how do you give a driver situational awareness? Do you give them a prompt and say — since you last gave up control, here’s what’s going on? No. No one knows the answer to that question yet, but it is key.”
The problem is human nature. The better the technology, the more comfortable and less attentive to the task a person is inclined to be. Tesla’s system is designed for drivers to keep their hands on the wheel so they maintain awareness of the road. However, the system will continue to operate if there are no hands on the wheel. It will periodically request drivers to put their hands back on the wheel, depending on the circumstances.
One driver testing the technology on a Florida highway was able to drive for nearly seven minutes without touching the wheel, due to the nature of the road.
“Overtrust could be an issue. Boredom could be an issue. People are not necessarily going to behave in the most ideal ways,” said Brian Ka-Jun Mok, one of the Stanford researchers. “If it gets to an area where the lane markings are missing or bad, autopilot will need you to take back over control, and it’s unable to negotiate that road — that might become a hazard.”
Although Tesla said it is confident in its system, it acknowledges it is not yet perfect.
Referring to the safety of pedestrians and cyclists, Tesla chief executive Elon Musk said Wednesday that Teslas “should actually brake before hitting them.” The vehicles, he said, “should handle them well, hopefully. Exercise caution at this early stage.”
Early signs indicate that it’s wishful thinking to expect Tesla drivers to keep their hands on the wheel. You can already find plenty of videos of drivers on YouTube cruising around without holding the wheel. Perhaps ironically, tech reporters given early access to test the technology have been some of the worst offenders.