Transportation

Federal Board Details Why Uber's Self-Driving Car Failed to Stop before Killing a Pedestrian

The car's automatic braking system was disabled at the time, according to the National Transportation Safety Board.

by Benjamin Raven, MLive.com / May 25, 2018
A vehicle drives by the scene of a fatality where a pedestrian was stuck by an Uber vehicle in autonomous mode, in Tempe, Ariz. (AP/Chris Carlson)

(TNS) —  Investigators report that the self-driving Uber SUV that struck and killed a woman in Arizona spotted the pedestrian six seconds before the fatal collision, but did not stop because the system to automatically apply brakes was disabled.

This information came from the National Transportation Safety Board, which released its preliminary findings on Thursday, May 24. In the report, federal investigators say Uber's modified, self-driving 2017 Volvo XC90 had its brakes designed for this type of dangerous situation disabled.

The system relied on the human backup driver to intervene but is not currently able to alert the driver of any dangerous situations. The crash occurred back on March 18 in Tempe, Arizona.

"The report states data obtained from the self-driving system shows the system first registered radar and lidar observations of the pedestrian about six seconds before impact, when the vehicle was traveling 43 mph," the NTSB's report reads.

"As the vehicle and pedestrian paths converged, the self-driving system software classified the pedestrian as an unknown object, as a vehicle, and then as a bicycle with varying expectations of future travel path. At 1.3 seconds before impact, the self-driving system determined that emergency braking was needed to mitigate a collision."

In the report, federal investigators say the woman was dressed in dark clothing, did not look before crossing the street, and was crossing outside of the legal crosswalk in an area "not directly illuminated by lighting."

Uber's reliance on the human backup driver to prevent this from happening is highlighted by the fact that video released by the Tempe Police Department showed its human backup driver with their head down until the moment they realized the vehicle they were behind the wheel of was about to strike someone.

The video shows the moment directly leading up to the collision with views from the outside and inside of the self-driving Volvo,

"In the report the NTSB said the self-driving system data showed the vehicle operator engaged the steering wheel less than a second before impact and began braking less than a second after impact," Thursday's report reads.

"The vehicle operator said in an NTSB interview that she had been monitoring the self-driving interface and that while her personal and business phones were in the vehicle neither were in use until after the crash.

"All aspects of the self-driving system were operating normally at the time of the crash, and there were no faults or diagnostic messages."

Uber suspended its self-driving operations across the U.S. as a federal investigation proceeded. The woman killed in the collision was identified as 49-year-old woman Elaine Herzberg. Tempe police Sgt. Ronald Elcock said that the pedestrian stepped into the street outside of the crosswalk and was immediately struck by the vehicle.

The death represented the first involving an autonomous vehicle being tested on public roads.

This report from the NTSB comes a day removed from Uber announcing it would end its self-driving operations in Arizona and lay off around 300 employees connected to the program. The ride-hailing company had suspended autonomous testing in Arizona, Pittsburgh, San Francisco and Toronto while the NTSB's investigation carried on.

It is important to note that these results are preliminary, and not final. The Associated Press reports that no deadline has been set on whether or not to pursue charges.

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