U.S. vehicle safety regulators stated on Friday they have opened a official safety probe into the autonomous driving method in cars made by Typical Motors Co’s robotaxi unit Cruise LLC after reviews of two accidents in rear-end crashes.

The National Highway Targeted visitors Protection Administration (NHTSA) stated it has gained notices of incidents in which self-driving Cruise automobiles “may possibly interact in inappropriately really hard braking or turn into immobilized.”

The agency claimed when both concerns “appear to be distinctive, they just about every result in the Cruise cars getting to be unexpected roadway hurdles.” The basic safety agency’s preliminary analysis covers 242 Cruise autonomous autos and is the initially step before it could search for a recall.

The investigation follows stories of 3 crashes in which Cruise motor vehicles were being struck from guiding by other automobiles just after the autonomous cars braked rapidly.

Cruise is presenting limited company in San Francisco with a small fleet of Chevrolet Bolt EVs. Cruise on Thursday introduced it had secured the initially of the two California permits it wants to demand riders evening and day throughout all of San Francisco, wherever it currently sells excursions in a little section of the metropolis.

Cruise stated it has “pushed nearly 700,000 absolutely autonomous miles in an extremely intricate urban natural environment with zero everyday living-threatening injuries or fatalities. … There’s constantly a balance in between healthier regulatory scrutiny and the innovation we desperately need to help you save lives, which is why we’ll keep on to totally cooperate with NHTSA or any regulator in achieving that shared purpose.”

NHTSA reported it programs to completely assess the likely protection-relevant challenges posed by these two forms of incidents and will assessment “the commonality and security logic of the tricky braking incidents” and the “frequency, period and protection penalties affiliated with the automobile immobilization incidents.”

GM shares ended up down 3.5% Friday at $36.31 in midday trading.

San Francisco officials did not quickly comment Friday on the NHTSA investigation, which could be a setback to the company’s deployment strategies.

Previous thirty day period, Cruise Chief Operating Officer Gil West explained to Reuters the business strategies to enter a “huge selection of marketplaces” and scale functions up to “1000’s of cars” in 2023.

NHTSA claimed the concerns “may possibly introduce multiple opportunity dangers this sort of as a collision with a Cruise automobile, risk to a stranded passenger exiting an immobilized Cruise car or truck, or obstruction of other targeted traffic which include unexpected emergency cars.”

The company explained it has three studies of Cruise vehicles’ automatic driving method “initiating a tricky braking maneuver in reaction to yet another road consumer that was swiftly approaching from the rear. In each individual circumstance, the other street user subsequently struck the rear of the Ads-geared up car.”

Cruise reported law enforcement did not ticket their cars in any of the 3 crashes.

NHTSA explained it has been notified of many reports involving Cruise vehicles running without onboard human supervision turning into immobilized, which “may well strand car or truck travellers in unsafe areas, these as lanes of vacation or intersections, and turn out to be an unexpected obstacle to other highway users.”

Cruise in September recalled and up to date software in 80 self-driving motor vehicles following a June crash in San Francisco that remaining two individuals injured. NHTSA said the recalled computer software could “incorrectly predict” an oncoming vehicle’s path. Cruise mentioned it experienced determined this strange situation would not recur just after the update.

GM and Cruise in February disclosed they petitioned the NHTSA for authorization to deploy some self-driving vehicles devoid of steering wheels, mirrors, turn signals or windshield wipers. That petition is nonetheless pending.