As automakers and technology companies race to get driverless cars onto the market, one expert is warning that the technology is nowhere near ready to hit America's roads.
The recent crash involving Tesla's Model S is a tragic example that even semi-automated programs like autopilot have risks, said Mary Cummings, Duke University Robotics director.
"These accidents are inevitable because the technology really has not been tested across the wide span of people and road conditions," she said in a recent interview with CNBC's "Power Lunch."
Joshua D. Brown died in a May crash when his Tesla's cameras failed to distinguish the white side of a turning tractor-trailer from a brightly lit sky, and didn't automatically activate its brakes. The National Highway Traffic Safety Administration (NHTSA) is investigating the accident. It is also looking into whether a non-fatal Tesla X crash July 1 involved autopilot mode.
Autopilot is a "semi-autonomous technology that helps drivers steer and stay in lanes," according to Reuters, which added that the autopilot function was still in test mode.
Tesla, however, has said that drivers should keep their hands on the wheel, even while the car was partially controlling its own movements.
For Cummings, one of the problems is that people immediately "check out" when a car or an airplane goes on autopilot—even though they are supposed to be paying attention. It's one of the risks the FBI noted in 2014, when it warned autonomous vehicles could easily become "lethal weapons" in the hands of the wrong driver.
"We've known this a long time because of aviation accidents," she said. "People will just do something called mind wandering and just be in their own heads and not paying attention at all."
That said, Cummins is a "huge fan" of driver-less technology. She hopes autos can be completely hands- and eyes-free by the time her 8-year-old daughter is sixteen.
The idea is that once the technology is in place, it will actually help reduce accidents. According to a study by consulting firm PTOLEMUS, there will be 380 million semi, highly or fully autonomous vehicles on the roads by 2030, which are expected to reduce the number of road accidents by 30 percent. About 1.25 million people around the globe die each year in car crashes, according to the World Health Organization.
Both the big automakers and tech companies are getting into the game. Google's driverless cars alone have self-driven more than 1.5 million miles during tests around the country. Audi, Delphi, Tesla, Honda and BMW are among those conducting tests, with BMW recently announcing it hopes to have its autonomous cars on the road by 2021.
But Cummings believes "we are in this very tenuous place right now" because cars are only partially capable of driving without a human, and there are problems in the implementation of the technology.
"If we are not going to be able to get that correct, then we probably shouldn't be using these kinds of modes of operation," she said.
—The Associated Press, Reuters and CNBC's Luke Graham contributed to this report.