Automakers reported nearly 400 crashes of vehicles with partially automated driver-assist systems, including 273 involving Teslas, according to statistics released Wednesday by the United States safety regulators.

The National Highway Traffic Safety Administration cautioned against using the numbers to compare automakers, saying it didn’t weight them by the number of vehicles from each manufacturer that use the systems, or how many miles those vehicles travelled.

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Automakers reported crashes from July of last year through May 15 under an order from the agency, which is examining such crashes broadly for the first time.

“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,” said Steven Cliff, the agency’s administrator.

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Tesla’s 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 vehicles with the systems on the road.

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

In a June 2021 order, NHTSA told more than 100 automakers and automated vehicle tech companies to report serious crashes within one day of learning about them and to disclose less-serious crashes by the 15th day of the following month. The agency is assessing how the systems perform and whether new regulations may be needed.

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

Tesla’s crash number may appear elevated somewhat because it uses telematics to monitor its vehicles and get real-time crash reports. Other automakers don’t have such capability, so their reports may come slower or crashes may not be reported at all, NHTSA said. A message was left seeking comment from Tesla.

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Tesla’s crashes accounted for nearly 70% of the 392 reported by the dozen automakers. Although the Austin, Texas, automaker 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.