US transport safety board finds Uber software at fault for fatal collision

25 May 2018

Uber self-driving SUV. Image: Sundry Photography/Shutterstock

The death of a pedestrian in Arizona has raised questions about Uber’s self-driving technology.

In March 2018, Elaine Herzberg was fatally struck by an Uber self-driving vehicle as she walked across the street with her bicycle in Tempe, Arizona.

Uber was then banned from testing self-driving vehicles by the governor of the state and an investigation by the US National Transportation Safety Board (NTSB) commenced.

The NSTB said that the full investigation would take a year or more to complete, but it yesterday (24 May) released its preliminary report on the incident, showing Uber’s self-driving technology to be unreliable.

Software at fault

According to its findings, the sensors on the self-driving vehicle worked entirely as expected. They spotted Herzberg around six seconds before impact, which should have afforded the car time to stop, given its speed of about 64kph.

The NTSB explained that Uber’s software then encountered some issues. “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.”

It continued, explaining the emergency braking issue the car encountered: “At 1.3 seconds before impact, the self-driving system determined that an emergency braking manoeuvre was needed to mitigate a collision.”

According to Uber, emergency braking manoeuvres are not enabled while the vehicle is under computer control, to reduce the potential for erratic vehicle behaviour. The vehicle operator is relied on to intervene and take action. The system is not designed to alert the operator.

The vehicle, a Volvo XC90 SUV, comes with emergency braking as standard but Uber automatically disabled this when its software was active. The test driver grabbed the steering wheel less than a second before the crash, braking shortly after impact.

The NSTB said the driver informed it that she was looking down to monitor a software touchscreen prior to the crash. “The operator is responsible for monitoring diagnostic messages that appear on an interface in the centre stack of the vehicle dash and tagging events of interest for subsequent review.”

Uber responds

An Uber spokesperson told The Register: “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 programme.

“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.”

Uber self-driving SUV. Image: Sundry Photography/Shutterstock

Ellen Tannam was a journalist with Silicon Republic, covering all manner of business and tech subjects