Car Industry

Uber self-driving car saw pedestrian 6 seconds before crash, NTSB says

The report also claims that Uber's car could have stopped in time, but it wasn't set up to do that on its own.

James Martin/CNET

The National Transportation Safety Board has released a preliminary report regarding Uber's fatal pedestrian collision in Tempe, Arizona, and initial results do not appear to be in anyone's favor.

The preliminary report, which does not contain probable cause and is still subject to future adjustments, points out that the pedestrian involved in the crash was wearing dark clothing in a poorly illuminated part of the road while carrying a bicycle lacking side reflectors. The victim tested positive for both marijuana and methamphetamines following the collision.

The orange line represents the mapped center of the lane, while the purple line shows the vehicle path, the center of which is represented by the green line.

NTSB

Regarding Uber's self-driving Volvo XC90, the report confirms that Uber does deactivate Volvo's own built-in driver assistance systems, including autonomous emergency braking, when operating in autonomous mode. Yet, while Uber's system includes its own autobrake capabilities, this system too is disabled during autonomous operation "to reduce the potential for erratic vehicle behavior."

According to data pulled from Uber's system, the pedestrian was first recognized about 6 seconds before the crash. The system's software first recognized the pedestrian as an unknown object, then as a vehicle, then finally as a bicycle. Then 1.3 seconds before the crash, the system determined braking was necessary to avoid a crash, but since Uber's autobrake was disabled, it was left to the human operator to apply the brakes. Despite the onus being on the operator, the report states that the system "is not designed to alert the operator."

Eventually, the operator grabbed the steering wheel and attempted to apply the brakes less than a second before impact. She told the NTSB she was "monitoring the self-driving interface" before the crash, but if there are no alerts to tell the driver to brake, it makes sense that she only attempted to do so after noticing the pedestrian in the road. 

"Over the course of the last two months, we've worked closely with the NTSB," an Uber spokesperson said in an emailed statement. "As their investigation continues, we've initiated our own safety review of our self-driving vehicles program. We've also brought on former NTSB Chair Christopher Hart to advise us on our overall safety culture, and we look forward to sharing more on the changes we'll make in the coming weeks."

The investigation is still ongoing, so the NTSB may have more data in the future. Meanwhile, Uber has ended its autonomous operations in Arizona entirely, saying it will instead focus on tests in Pennsylvania.