A self-driving Uber vehicle that hit and killed a pedestrian in Tempe earlier this year detected the victim six seconds before impact.
However, the Uber system did not register a need for emergency braking until 1.3 seconds before impact and the system was not designed to alert the driver of a possible collision.
That’s according to a preliminary report from the National Transportation Safety Board released Thursday. The report does not give a probable cause for the incident as the investigation is ongoing.
“The software should have been able to predict that the car was on a collision path with this quote-on-quote obstacle and it looked like it did not make that prediction early enough,” said Dr. Raj Rajkumar is a professor at Carnegie Mellon University who has studied autonomous vehicle technology for 15 years. He said several factors could have contributed to the crash.
The Volvo XC90 SUV was pre-equipped with automatic emergency braking, but the function was disabled while the vehicle was in autonomous mode.
Rajkumar said the system was likely shut off to prevent interference between Uber and Volvo’s separate software.
“According to Uber, emergency braking maneuvers are not enabled while the vehicle is under computer control, to reduce the potential for erratic vehicle behaviour,” the report said.
RELATED: Uber Shutting Down Self-Driving Operations In Arizona
The system relied on the driver to intervene, but did not have a process to alert the driver of problems.
ASU Computer Engineering Professor Dr. Lina Karam said another problem is an apparent contradiction in Uber’s policy.
“We’re relying on an attentive operator to make decisions here and that’s why we disabled the braking system, but at the same time that operator was required also to be monitoring data which then requires them to be inattentive,” Karam said.
In the minutes before the crash, the driver looked away from the road several times. There console in the center of the vehicle that displays information about the self-driving system.
“The operator is responsible for monitoring diagnostic messages...and tagging events of interest for subsequent review,” the report said.
Karam noted future self-driving endeavors should consider outlining specific qualifications for operators.
“To have a prolonged focus requires some skills and talents and not everybody can do it.” Karam said. Having two passengers in the car would also allow the assignment of specific tasks and could reduce distraction.
The report included information about the pedestrian victim as well.
“The pedestrian was dressed in dark clothing, did not look in the direction of the vehicle until just before impact, and crossed the road in a section not directly illuminated by lighting,” the report stated.
Toxicology reports show the woman tested positive for methamphetamine and marijuana.
Uber announced it’s ending self-driving operations in Arizona Wednesday morning.
Uber declined to comment on the findings, but issued the following statement.
“Over the course of the last two months, we’ve worked closely with the NTSB. 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.”
Preliminary Report From The National Transportation Safety Board
