Making matters worse, a camera mounted inside the Volvo XC90 test car showed the backup driver not watching the road in the seconds leading up to the crash. Backup drivers are still required in most autonomous vehicle tests to take control if the car fails or gets stuck.
Both videos are likely to heighten already growing concerns about self-driving cars and could lead to stricter regulation, industry experts told The Connected Car.
The accident in Tempe on Sunday, March 18, which took the life of Elaine Herzberg, 49, has already led Uber to temporarily halt all self-driving tests in the US. Toyota Research Institute in Silicon Valley has also stopped its road tests for now, and activists have called for a nationwide moratorium to get autonomous cars off the roads.
Late on Wednesday, the Tempe Police Department released two brief videos captured by cameras on the Volvo just before it struck Herzberg. An investigation of the incident continues.
Herzberg was walking her bike from west to east across Mill Avenue in Tempe at about 10 p.m. when the Volvo, traveling north at 38mph, ran into her. Mill Avenue is a flat, multilane street with an island in the middle. The video shows a person emerging from the shadows and walking into the Volvo's lane, lit by its headlights. The crash happens within seconds.
Self-driving cars such as Uber's Volvos are equipped with multiple sensors, including cameras, radar and Lidar, to detect cars and other objects around them even in darkness. The type of Lidar typically used on Uber autonomous cars is supposed to have a range of more than 100 meters, which should have given the Volvo a few seconds to slow down and swerve, if not stop, said Gartner analyst Michael Ramsey.
"It's amazing to me that there was no reaction," Ramsey said. "The car did nothing, even up to the last second. That's bizarre."
This may have happened either because the sensor system didn't work or because the computer analyzing the incoming data failed to recognize the object crossing the road as a pedestrian, he said.
The interior video shows the backup driver looking down, possibly at a phone, for most of the several seconds before the crash. At the end, she suddenly looks up in shock.
This raises questions about how well Uber manages its testing program, Ramsey said. There are even systems on the market now, using cameras pointed at the driver, that can detect drowsiness or inattention and set off alerts.
But being a backup driver in an autonomous car comes with a boredom hazard that any company testing the technology needs to address, he said. For one thing, Uber ought to be assigning the drivers to short shifts. An average person behind the wheel of a self-driving car could probably pay attention for half an hour, Ramsey said. After even two hours, it would start to get difficult.
"That's a really long time to be doing nothing," Ramsey said. "I promise you that you would probably be looking at your phone."
The videos make it even more likely that what happened in Tempe will cool investors, regulators and the public toward autonomous cars, Ramsey said. A wave of anticipation has driven investment, attention and startup activity, but if the hype hadn't already peaked, it surely has now, he said.
— Stephen Lawson is a freelance writer based in San Francisco. Follow him on Twitter @sdlawsonmedia.