Cruise, the self-driving subsidiary of General Motors Co. GM, -1.42% that operates a robotaxi service in San Francisco, recalled the software on 300 of its autonomous cars after one rear-ended a bus in March.
While no one was injured and the crash caused only minor damage, “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 Chief Executive Kyle Vogt said in a blog post Friday.
Cruise is currently seeking approval of around-the-clock driverless taxi service in San Francisco (it’s currently restricted to certain neighborhoods and times of day), and permission to test its autonomous cars across all of California.
But its technology has been criticized in San Francisco following a series of glitches in which driverless Cruise cars have stopped in the middle of streets, blocked traffic and disrupted emergency responders, spurring complaints by San Francisco lawmakers and an investigation by federal safety regulators.
The March 23 fender-bender was “exceptionally rare,” Vogt said in his blog post, explaining that the car applied the brakes too late because it did not properly recognize an articulated bus (that is, a bus with two sections connected by a flexible joint — a common feature on San Francisco’s most heavily trafficked bus lines) that was pulling into traffic.
“Our vehicles encounter buses like this one every day, but we’d never caused this kind of collision before,” Vogt said.
Cruise engineers identified the problem and updated the software within two days, Vogt said, and “the results from our testing indicated that this specific issue would not recur after the update.”
The company notified the National Highway Traffic Safety Administration of the software recall. “No other collisions have occurred as a result of this issue,” Cruise told the NHTSA.