The uptick in crashes coincides with Tesla’s aggressive rollout of Full Self-Driving, which has expanded from about 12,000 users to nearly 400,000 in a little more than a year. Nearly two-thirds of all driver-assistance crashes that Tesla has reported to NHTSA occurred in the past year.

Philip Koopman, a Carnegie Mellon University professor who has conducted research on autonomous-vehicle safety for 25 years, said the prevalence of Teslas in the data raises crucial questions.

“A significantly higher number certainly is a cause for concern,” he said. “We need to understand if it’s due to actually worse crashes or if there’s some other factor such as a dramatically larger number of miles being driven with Autopilot on.”

In February, Tesla issued a recall of more than 360,000 vehicles equipped with Full Self-Driving over concerns that the software prompted its vehicles to disobey traffic lights, stop signs and speed limits.