US automakers reported nearly 400 crashes in 10 months involving vehicles with partially automated driver-assist systems, including 273 with Teslas, according to statistics released by federal safety regulators.

The National Highway Traffic Safety Administration (NHTSA) cautioned against using the numbers to compare automakers, saying it did not weight them by the number of vehicles from each manufacturer or how many miles those vehicles traveled.

Automakers reported crashes from July 2021 through 15 May 2022 under an order from the agency.

Steven Cliff, the NHTSA administrator, said: “As we gather more data, NHTSA will be able to better identify any emerging risks or trends and learn more about how these technologies are performing in the real world.”

Tesla crashes happened while vehicles were using Autopilot, Full Self-Driving, Traffic Aware Cruise Control or other driver-assist systems that have some control over speed and steering. The company has about 830,000 such vehicles on the road.

The next closest of a dozen automakers that reported crashes was Honda, with 90. Honda says it has about 6m vehicles on US roads with such systems. Subaru was next with 10. All other automakers reported five or fewer crashes.

In a June 2021 order, NHTSA told more than 100 automakers and tech companies to report serious crashes within one day of learning about them and to disclose less-serious crashes by the 15th day the following month.

Six people were killed in crashes involving driver-assist systems and five were seriously hurt, NHTSA said. Of the deaths, five were in Teslas and one was reported by Ford. Three serious injuries were in Teslas. Honda and Ford each reported one.

Tesla’s crash number may appear elevated because it gets real-time crash reports. Other automakers do not, so their reports may come slower or crashes may not be reported at all, NHTSA said.

Tesla’s crashes accounted for nearly 70% of 392 reported. Although Tesla calls its systems Autopilot and Full Self-Driving, it says the vehicles cannot drive themselves and the drivers must be ready to intervene at all times.

A message was left seeking comment from Tesla.

Auto safety advocates said driver-assist and self-driving systems have potential to save lives, but not until NHTSA sets minimum performance standards and requires safety improvements.

“It’s clear that US road users are unwitting participants in beta testing of automated driving technology,” said Cathy Chase, president of Advocates for Highway and Auto Safety.

Ed Markey, a US senator from Massachusetts, said although the NHTSA data had limitations, it was not isolated evidence that Tesla has ignored regulations and putting the public in danger.

There have been “a never ending parade of reports” of Teslas on automated systems rolling through stop signs or braking for no reason, he said. NHTSA also is investigating Teslas that crash into parked emergency vehicles.

“As today’s data suggests, this contempt for auto safety laws has real-world consequences,” Markey said, urging NHTSA to take enforcement action.

NHTSA has used the data to seek a recall, open investigations and provide information for existing inquiries, officials said.

“This will help our investigators quickly identify potential defect trends that can emerge,” Cliff said. “These data will also help us identify crashes that we want to investigate and provide more information about how people in other vehicles interact with the vehicles.”

NHTSA’s order also covered companies running fully autonomous vehicles: 25 reported a total of 130 crashes. Google spinoff Waymo led with 62, followed by Transdev Alternative Services with 34 and General Motors-controlled Cruise with 23.

Waymo said it had more than 700 autonomous vehicles in its fleet. The company is running a ride-hailing service in Arizona and testing one in California. The company said all crashes happened at low speeds, with air bags inflating in two.

In 108 crashes involving fully autonomous vehicles, no fatalities were reported and there was only one serious injury. In most crashes, vehicles were struck from the rear.