What the Uber fatality reveals

While self-driving vehicles can reliably see their surroundings using sophisticated sensors and cameras, the software doesn't always understand what it detects. New details have been released about Uber's autonomous vehicle that struck and killed a woman in Tempe, Arizona, which indicate that neither the self-driving system nor the human safety driver behind the wheel hit the brakes when she apparently stepped off a median and onto the roadway, according to an account the Tempe police chief gave to the San Francisco Chronicle.

The human driver told police he didn't see the pedestrian coming, and the autonomous system behaved as if it hadn't either. “The real challenge is you need to distinguish the difference between people and cars and bushes and paper bags and anything else that could be out in the road environment,” said Matthew Johnson-Roberson, an engineering professor at the University of Michigan who works with Ford Motor Co. on autonomous vehicle research, to BloombergTechnology. “The detection algorithms may have failed to detect the person or distinguish her from a bush.” After the Uber collision, the car continued traveling at 38 miles per hour, according to the Tempe police chief, and the driver told police he wasn't aware of the pedestrian until the car collided with her. A police spokeswoman said the speed limit where the accident occurred is 35 mph. This highlights what Johnson-Roberson describes as a shortcoming in robot reasoning. “I live in Ann Arbor, a college town,” Johnson-Roberson said. “So on football weekends, when there’s a bunch of drunk college kids, I drive at a lower speed. Those are the kind of human decisions we make to anticipate a situation, and that’s hard with autonomous cars. We’re not there yet.”  Autonomous vehicles also struggle to master weather elements. Snow, ice and rain can obscure sensors and render the most advanced computing power useless. That's one reason most self-driving cars are being tested in sunny climates like Arizona and Texas. The death is a tragedy for her family, and also a public-relations disaster for Uber and other companies that want to test their technology on public roadways. Waymo announced last year it would begin testing vehicles with no backup drivers.