U.S. opens probe of Cruise robotaxi braking, clogging traffic

U.S. safety regulators are investigating reports that autonomous robotaxis run by General Motors' Cruise LLC can stop too quickly or unexpectedly stop moving, potentially stranding passengers.

The National Highway Traffic Safety Administration says it opened the probe after getting three reports of Cruise autonomous vehicles braking so hard that they were hit from behind by other vehicles. At the time, robotaxis were staffed by human safety drivers.

The agency also has multiple reports of Cruise robotaxis without human safety drivers becoming immobilized in San Francisco traffic, possibly stranding passengers and blocking lanes.

The reports of immobilized autonomous vehicles came from discussions with Cruise, media reports and local authorities, NHTSA said in an investigation document posted Friday on its website.

Could lead to a recall

There have been two reports of related injuries, including serious injuries to a bicyclist last March, according to the NHTSA crash database.

NHTSA says it will determine how often the problems happen and any potential safety issues they cause. The probe, which covers an estimated 242 Cruise autonomous vehicles, could bring a recall.

Cruise spokesman Drew Pusateri said the company is co-operating in the investigation, and that its vehicles have driven nearly 700,000 autonomous miles (1.1 million kilometres) in a complex city with no life-threatening injuries or deaths.

"This is against the backdrop of over 40,000 deaths each year on American roads," he wrote. "There's always a balance between healthy regulatory scrutiny and the innovation we desperately need to save lives."

He said police didn't issue tickets in any of the crashes, and that in each case, the autonomous vehicle was responding to aggressive or erratic behaviour from other road users.

"The AV was working to minimize collision severity and risk of harm, which is exactly what it did," Pusateri wrote.

Stoppages rare, company says

In the clogged traffic incidents, Pusateri wrote that whenever Cruise technology isn't extremely confident in moving, it's designed to be conservative, turning on hazard lights and coming to a safe stop.

"If needed, Cruise personnel are physically dispatched to retrieve the vehicle as quickly as possible," Pusateri wrote. Such stoppages are rare and have not caused any crashes, he wrote.

NHTSA said Cruise reported the three rear-end accidents under a 2021 order requiring automated vehicle companies to notify the agency of crashes.

Reports of Cruise robotaxis becoming immobilized in traffic came from the San Francisco Municipal Transportation Agency and the San Francisco County Transportation Authority, the agency said.

Cruise vehicles may strand passengers in unsafe locations, such as travel lanes or intersections, increasing the risk to exiting passengers. And they can become obstacles to other road users, causing them to make unsafe manoeuvres to avoid collisions.

"The vehicles may also present a secondary safety risk, by obstructing the paths of emergency response vehicles and thereby delaying their emergency response times," the agency said in the document.

Critical time for industry

The probe comes at an important time for Cruise, which in June started charging passengers for autonomous rides without human safety drivers in San Francisco.

It's also a critical time for the autonomous vehicle industry, with Google spinoff Waymo running a robotaxi service in the Phoenix area with plans to expand to San Francisco. Other companies are also moving toward services without human safety drivers.

San Francisco-based Cruise plans to expand the service to Phoenix and Austin, Texas. The startup owned by GM has been testing autonomous Chevrolet Bolt electric vehicles for several years.

In September, Cruise revealed that it recalled 80 of its driverless vehicles for a software update after one of the cars was involved in an accident that resulted in minor injuries.

Cruise told the National Highway Traffic Safety Administration that one of its vehicles was making an unprotected left turn at an intersection when it was hit by an oncoming vehicle. The Cruise vehicle had to be towed away from the scene, according to the regulatory filing.

GM acquired a majority stake in Cruise when it was a startup in 2016. The company invested to take 80 per cent stake in the company last May.