We’re now getting some official details on a fatal crash that occurred back in March between an Uber self-driving Volvo XC90 and a woman walking a bicycle across the street. Preliminary findings that were leaked earlier this month claimed that the Volvo did see Elaine Herzberg as she was crossing the street at night. The report did not, however, explain why the vehicle still proceeded along its intended path, crashing into Herzberg.
The official National Transportation Safety Board (NTSB) preliminary report is shedding additional light on the situation, and confirms that the Volvo did indeed see the pedestrian. According to the report, the vehicle operator left the Uber garage at 9:14pm to travel along an “established test route”. The vehicle had been driving in full autonomous mode for around 20 minutes right up until the crash occurred.
The report goes on to say that the self-driving system actually saw Herzberg six seconds before the impact occurred. For an autonomous system, that should have been more than enough to time for corrective action to be taken. Between this initial “engagement” and the impact, the system first identified Herzberg as an “unknown object”, then as a vehicle, before finally correctly identifying [at least partially] that a bicycle was within its path.
It wasn’t until 1.3 seconds before impact that the self-driving system had determined that the brakes should be applied to lessen the force of the imminent impact. But here’s the big takeaway from the report; auto braking was disabled on the Volvo. The NTSB writes:
According to Uber, emergency braking maneuvers are not enabled while the vehicle is under computer control, to reduce the potential for erratic vehicle behavior. The vehicle operator is relied on to intervene and take action. The system is not designed to alert the operator.
As we saw from the in-vehicle footage that was released shortly after the crash, the human driver behind the wheel of the Volvo wasn’t even paying attention to the road prior to the crash. She was looking down at the autonomous vehicle interface in the dash and didn’t react until it was too late (less than a second before impact). The vehicle had been traveling at 43 mph prior to impact and actually hit Herzberg while traveling at approximately 39 mph.
The NTSB hasn’t made any final decisions on who may or may not be at fault in this tragic accident, but Uber seems to put at least some onus on the “driver”. The NTSB report adds:
According to Uber, the developmental self-driving system relies on an attentive operator to intervene if the system fails to perform appropriately during testing. In addition, the operator is responsible for monitoring diagnostic messages that appear on an interface in the center stack of the vehicle dash and tagging events of interest for subsequent review.
It should be noted that Uber announced yesterday that it is suspending its self-driving vehicle program in Arizona.