Tesla vehicles have been involved in most of the crashes involving "Level 2" driver-assistance systems reported to the government, according to US data released Wednesday.

The electric autos accounted for 273 of 392 crashes reported under a June 2021 National Highway Traffic Safety Administration directive requiring manufacturers to submit data on crashes for Level 2 driver-assistance programs, which aid with braking and steering but require the driver to remain fully engaged at all times.

NHTSA last week expanded a probe into Tesla's "Autopilot" system, which Tesla Chief Executive Elon Musk has argued reduces the risk of accidents when used properly.

Crashes are reportable if the assistance system was used within 30 seconds of the incident and if the episode resulted in a fatality, a vehicle tow-away, airbag deployment or injury to a pedestrian or other "vulnerable" road user.

"The data released today are part of our commitment to transparency, accountability and public safety," said NHTSA Administrator Steven Cliff.

"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 Chief Executive Elon Musk has maintained 'Autopilot' enhances driver safety as the government expands a probe of the system
Tesla Chief Executive Elon Musk has maintained 'Autopilot' enhances driver safety as the government expands a probe of the system TED Conferences, LLC via AFP / Ryan Lash

NHTSA did not criticize Tesla or other automakers in the report and cautioned of imperfections in the data.

Some of the incidents may have been reported multiple times by the same entity.

"Consequently, the overall number of reports submitted does not equate to the total number of incidents and is not a meaningful safety metric," NHTSA said in the report.

Another issue is that the manufacturers who are required to report the incidents can only do so if and when the vehicle owner reports the incident. As a result, some incidents may not have been reported, NHTSA said.

NHTSA last week said it widened a probe of Tesla to whether "Autopilot and associated Tesla systems may exacerbate human factors or behavioral safety risks by undermining the effectiveness of the driver's supervision."

The action moves NHTSA a step closer to a potential recall of Tesla vehicles.