A recent study by the National Highway Traffic Safety Administration (NHTSA) and supported by auto makers found some drivers took as long as 17 seconds to respond to a takeover request from the autonomous control system to resume control of the car. That's time drivers don't have, especially on a fast-moving freeway.
There's plenty of evidence that drivers have trouble staying engaged when driving becomes monotonous or there's nothing for them to do.
Watch drivers at any stop light and you'll see them looking down at their smartphones, while boredom pushes some people to far riskier behavior.
In studies of college students in South Dakota, who spend hours driving conventional cars on long, straight roads with little traffic, multitasking is the norm. Without an obvious need to stay focused on the road, students start texting, studying, watching movies and even having sex, said Cindy Struckman-Johnson, a professor at the University of South Dakota.
"It's amazing there aren't more accidents," she said.
Toyota's Highway Teammate, a modified Lexus GS the company is using to trial autonomous driving technology. Credit: Toyota Motor
In a 2014 study, a third of men and 9 percent of women surveyed at the university reported engaging in sexual acts while driving. Almost half occurred at speeds between 61 and 80 miles per hour, and over a third reported their cars drifted into another lane, or that they ended up speeding because they weren't paying full attention.
Struckman-Johnson said she's worried that as autopilot systems get better, drivers will fall to more and more distractions and care even less about keeping an eye on the road.
A new type of accident
Autonomous technology is new enough that there don't appear to have been any major accidents yet caused by drivers not paying attention to the road. But they're probably coming.
"In the future, i think we're going to have a particular type of accident related to extreme distraction brought on by the features of autonomous car," said Struckman-Johnson. "The car becomes complicit in the accident."
But when that happens, it's important people don't overreact and conclude that self-driving cars aren't safe, NASA's Casner said. The technology promises to virtually eliminate rear-end collisions -- the most common type of car accident -- and is likely to save lives in other situations.
"There's the fear that there will be the one accident that people will react to, and even though we’ve saved thousands of lives in other categories, there'll be an overreaction because ‘A person was killed by a computer’," he said.
Nissan's IDS concept car, unveiled at the Tokyo Motor Show on Oct. 28, 2015, combines electric vehicle and autonomous driving technology. Here it is seen driving in an EV lane. Credit: Nissan
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