Uber had equipped the test vehicle with a developmental self-driving system. The system consisted of forward- and side-facing cameras, radars, LIDAR, navigation sensors, and a computing and data storage unit integrated into the vehicle. Uber had also equipped the vehicle with an aftermarket camera system that was mounted in the windshield and rear window and that provided additional front and rear videos, along with an inward-facing view of the vehicle operator. In total, 10 camera views were recorded over the course of the entire trip.
The Volvo-factory installed driving assist and collision avoidance system named City Safety was disabled by Uber. According to Uber the self-driving system relies on the safety driver to interfere in emergencies.
According to the data retrieved from the radars and lidars the pedestrian was detected 6 seconds before impact, when the car was traveling with 43 miles per hour. The system classified the pedestrian first as unknown object, then as vehicle, then as bicycle with various options of an expected path. 1.3 seconds before the collision the system discovered that an emergency stop has to be activated to avoid a collision
But when in computer control the emergency brake system is disable to avoid erratic behavior in case of so-called false positives, leading to sudden stops in flowing traffic at higher speed. In such a scenario the system is programmed to rely on a human safety driver taking action.
The safety driver reacted less than a second before the impact by steering the steering wheel. The collision happened at a speed of 39 miles per hour, the safety driver used the brakes one second after the impact. The self-driving system was operating normal – a.k.a worked as designed.
The videos from the vehicle cameras show a dark dressed pedestrian crossing the street without looking at the oncoming vehicle. The bicycle had no side reflectors.
The inside cameras show a safety driver looking down inside the car. The driver stated in interview with the NTSB that she was monitoring the self-driving console. While she had both a private and a business phone in the vehicle, they were only used after the impact to call 911.
Emergency responders at the crash scene confirmed that the safety driver did not look intoxicated. Toxicological examination on the pedestrian showed results for methamphetamine and marijuana.
In the meantime, Uber has ceased temporarily all operations in developing self-driving vehicles, lost the test license for self-driving in Arizona and let the one in California expire, and also laid off all employees in Arizona.
This article has also been published in German.