Police in the US state of Arizona on Wednesday released a video showing the moments before a self-driving Uber vehicle drove into a pedestrian, raising questions over the safety of autonomous transportation.

Uber halted testing of self-driving vehicles in response to Sunday's night accident in Tempe, a suburb of Phoenix. The pedestrian, 49-year-old Elaine Herzberg, died. It was the first death caused an autonomous vehicle.

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The video shows the Volvo in self-driving mode with a backup driver behind the wheel. An interior view shows the driver looking down twice. The driver then looks up and appears shocked just before hitting Herzberg.

A video segment from the exterior of the vehicle shows it driving down the road as Herzberg emerges from the dark pushing her bike.  The headlights shine on her just before she is hit.

Experts said the autonomous vehicle's radar and Lidar systems should have noticed Herzberg, who appeared to be jaywalking across a four-lane highway.

"The sensors should have detected the pedestrian in this case; the cameras were likely useless but both the radars and the Lidar must have picked up the pedestrian," Raj Rajkumar, a professor at Carnegie Mellon, told Reuters news agency.

Though no information is available, one would have to conclude based on this video alone, that there are problems in the Uber vehicle software that need to be rectified," he said.

Bryant Walker Smith, a University of South Carolina law professor who studies autonomous vehicles, told The Associated Press that although the video doesn't provide a full picture it is "strongly suggestive of multiple failures of Uber and its system, its automated system, and its safety driver."

"The victim did not come out of nowhere. She's moving on a dark road, but it's an open road, so Lidar (laser) and radar should have detected and classified her," Smith said.

Police and the National Transportation Safety Board are investigating the crash. The Arizona Republic newspaper quoted Tempe Police Chief Sylvia Moir as saying the crash was "unavoidable" based on an initial investigation and a review of the video.

The incident may slow down testing of autonomous vehicles and renew calls for tighter regulation of an emerging technology.

cw/sms (AP, Reuters)

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