The National Highway Traffic Safety Administration is investigating three crashes involving driverless taxis operated by General Motors Co.’s Cruise LLC, just as the autonomous-vehicle division is poised to expand service.

Officials are looking into Cruise vehicles that braked suddenly — resulting in three crashes in which human motorists rear-ended the robotaxi — or cars that unexpectedly pulled over and stopped, according to a NHTSA document posted December 16. The agency said it’s unknown if there have been accidents related to the second issue.

A spokesperson for Cruise said it’s rare for cars to pull over, and that there have been no accidents when that’s happened.

Cruise is expanding its robotaxi service across San Francisco and preparing to charge for rides in Austin, Texas, and Phoenix. Cruise’s business is a big piece of GM Chief Executive Officer Mary Barra’s quest to double revenue by 2030. The startup, which is majority owned by GM, has a goal of $1 billion in revenue in 2025 and $50 billion by 2030.

GM shares were down 2.8% to $36.55 at 10:55 a.m. December 16 in New York.
What’s at issue is how the cars interact with human drivers on public roads. NHTSA is looking at whether either problem amounts to a defect.

Cruise said that in all three crashes involving sudden braking, the vehicles had a safety driver, and that the cars’ robotic systems were responding to aggressive or erratic human drivers in other vehicles. The self-driving cars were trying to minimize collision severity and risk of harm, said company spokesman Drew Pusateri.

Tricky Situations

In instances where a Cruise car has a tough time navigating, the vehicle turns on its hazard lights and pulls over, potentially stranding passengers in unsafe locations or endangering other drivers, NHTSA said.

“These immobilizations may increase the risk to exiting passengers,” the agency said. “Further, immobilization may cause other road users to make abrupt or unsafe maneuvers to avoid colliding with the immobilized Cruise vehicle, by, for example, diverting into oncoming lanes of traffic or into bike lanes.”

Cruise cars shut down an intersection in San Francisco in June for more than an hour before company personnel could get to the scene and move them.

The company said it plans to stay on course with its expansion, and that the technology is safe for the road.

“Cruise’s safety record is publicly reported and includes having driven nearly 700,000 fully autonomous miles in an extremely complex urban environment with zero life-threatening injuries or fatalities,” Pusateri said in a statement. “This is against the backdrop of over 40,000 deaths each year on American roads.”