Uber suspends self-driving car tests after first fatal pedestrian crash

A woman in Tempe, Ariz., has died after being hit by a self-driving car operated by Uber, in what appears to be the first known death of a pedestrian struck by an autonomous vehicle on a public road.

The Uber vehicle was in autonomous mode with a human safety driver at the wheel when it struck the woman, who was crossing the street outside of a crosswalk, the Tempe police said in a statement. The episode happened on Sunday around 10 p.m. The woman was not publicly identified.

Uber said it had suspended testing of its self-driving cars in Tempe, Pittsburgh, San Francisco and Toronto.

“Our hearts go out to the victim’s family. We are fully cooperating with local authorities in their investigation of this incident,” an Uber spokeswoman, Sarah Abboud, said in a statement.

The fatal crash will most likely raise questions about regulations for self-driving cars. Testing of self-driving cars is already underway for vehicles that have a human driver ready to take over if something goes wrong, but states are starting to allow companies to test cars without a person in the driver’s seat. This month, California said that, in April, it would start allowing companies to test autonomous vehicles without anyone behind the wheel.

Arizona already allows self-driving cars to operate without a driver behind the wheel. Since late last year, Waymo, the self-driving car unit from Google’s parent company Alphabet, has been using cars without a human in the driver’s seat to pick up and drop off passengers there. The state has largely taken a hands-off approach, promising that it would help keep the driverless car industry free from regulation. As a result, technology companies have flocked to Arizona to test their self-driving vehicles.

Autonomous cars are expected to ultimately be safer than human drivers, because they don’t get distracted and always observe traffic laws. However, researchers working on the technology have struggled with how to teach the autonomous systems to adjust for unpredictable human driving or behavior.

An Uber self-driving car was involved in another crash a year ago in Tempe. In that collision, one of Uber’s Volvo XC90 sport utility vehicles was hit when the driver of another car failed to yield, causing the Uber vehicle to roll over onto its side. The car was in self-driving mode with a safety driver behind the wheel, but police said the autonomous vehicle had not been at fault.

In 2016, a man driving his Tesla using Autopilot, the car company’s self-driving software, died on a state highway in Florida when it crashed into a tractor-trailer that was crossing the road in front of his car. Federal regulators later ruled there were no defects in the system to cause the accident.

The National Transportation Safety Board was sending a small team of investigators to Arizona to gather information about the Uber crash, said Eric Weiss, an N.T.S.B. spokesman.