General Motors’ self-driving subsidiary Cruise is recalling 300 robotaxis to update its automated driving software after one of its driverless vehicles crashed into the back of a San Francisco bus.
Cruise said in a report (pdf) with the National Highway Traffic Safety Administration (NHTSA) that the software may cause a crash because it inaccurately predicts the movement of “articulated” vehicles, such as buses, tractors, or trailers.
This recall follows a crash on March 23 when a self-driving Cruise car inaccurately predicted the movement of a San Francisco Municipal Transit Authority bus and hit the rear of the bus going about 10 mph, according to the NHTSA filing.
“Cruise determined that the collision was caused by an issue related to prediction of the unique movements of articulated vehicles in rare circumstances,” the company said in documents.
There were no reported injuries in the crash. Cruise said the incident resulted in minor damage to the front fender of the automated vehicle (AV).
The company said it did the recall to be transparent and add to public understanding of the crash.
“Fender benders like this rarely happen to our AVs, but this incident was unique,” Cruise co-founder and CEO Kyle Vogt wrote in a blog post on Friday.
“We do not expect our vehicles to run into the back of a city bus under any conditions, so even a single incident like this was worthy of immediate and careful study.”
Cruise has determined that another incident such as this would not recur after a software update on all affected vehicles on March 25, the filing states.
“We will undoubtedly continue to discover ways in which we can improve,” Vogt said in the blog.
“These continuous improvements are likely to make voluntary recalls commonplace. We believe this is one of the great benefits of autonomous vehicles compared to human drivers; our entire fleet of AVs is able to rapidly improve, and we are able to carefully monitor that progress over time.”
Cruise in September disclosed that it recalled and updated software in 80 self-driving vehicles after a June crash in San Francisco that left two people injured.
NHTSA last year said the software could “incorrectly predict” an oncoming vehicle’s path.
NHTSA in December opened a formal safety probe into the Cruise autonomous driving system after it received reports of incidents in which self-driving Cruise vehicles “may engage in inappropriately hard braking or become immobilized.”
Reuters contributed to this report.