10 confused Cruise robotaxis create an autonomous traffic jam in San Francisco

On Friday, the North Beach neighborhood of San Francisco was briefly clogged with traffic after autonomous taxis froze at a busy intersection. The jam consisted of at least 10 driverless Chevy Bolts operated by Cruise, General Motors’ self-driving car subsidiary. 

“One of them was stopped at the top of the hill for no apparent reason,” witness Valerie Jacobson told NBC Bay Area.

The mishap coincided with a music festival taking place in nearby Golden Gate Park. Cruise blamed the festival for interfering with network connections to the cars.

“A large festival posed wireless bandwidth constraints causing delayed connectivity to our vehicles. We are actively investigating and working on solutions to prevent this from happening again. We apologize to those who were impacted,” said a statement put out by Cruise on social media.

The cluster comes just a day after the state’s Public Utilities Commission ruled 3-1 in favor of letting Cruise and Waymo expand their driverless taxi operations. Waymo is owned by Alphabet, parent company of Google, and uses Jaguar I-Pace electric crossovers. The ruling allowed the companies to conduct robotaxi operations 24/7 throughout San Francisco.

San Francisco Board of Supervisors President Aaron Peskin cautioned that “these things are not ready for prime time,” when speaking to NBC Bay Area. “[It’s] scary as heck if you think about the fact that moving these vehicles out of traffic requires cell service,” he added.

Peskin pointed out that cell service disruption could occur because of a natural disaster. In a situation like that the driverless cars could prevent emergency vehicles from getting through, or block evacuation routes. In an interview with ABC7 San Francisco, he drove the point home: “If there’s a power outage or if there’s a natural disaster like we just saw in Lahaina that these cars could congest our streets at the precise time when we would be needing to deploy emergency apparatus.”

Though the traffic jam cleared after about 20 minutes, this isn’t the first time robotaxis have caused confusion in situations that human drivers would have been able to figure out in seconds. When a robotaxi encounters a confusing situation, it seems to default to simply stopping.

In April, a Cruise robotaxi collided with a city bus, and another was unable to follow a police officer’s instructions to pull over. A similar Cruise traffic jam of eight vehicles blocked city streets for hours last summer, but the cause was never explained. Last December, NHTSA opened an investigation into Cruise for its vehicles’ greater-than-average rate of hard braking and immobilization.