Federal regulator finds Tesla Autopilot has 'critical safety gap' linked to hundreds of collisions

Federal authorities say a "critical safety gap" in Tesla's Autopilot system contributed to at least 467 collisions, 13 resulting in fatalities and "many others" resulting in serious injuries.

The findings come from a National Highway Traffic Safety Administration analysis of 956 crashes in which Tesla Autopilot was thought to have been in use. The results of the nearly three-year investigation were published Friday.

Tesla's Autopilot design has "led to foreseeable misuse and avoidable crashes," the NHTSA report said. The system did not "sufficiently ensure driver attention and appropriate use."

The agency also said it was opening a new probe into the effectiveness of a software update Tesla previously issued as part of a recall in December. That update was meant to fix Autopilot defects that NHTSA identified as part of this same investigation.

The voluntary recall via an over-the-air software update covered 2 million Tesla vehicles in the U.S., and was supposed to specifically improve driver monitoring systems in Teslas equipped with Autopilot.

NHTSA suggested in its report Friday that the software update was probably inadequate, since more crashes linked to Autopilot continue to be reported.

In one recent example, a Tesla driver in Snohomish County, Washington, struck and killed a motorcyclist on April 19, according to records obtained by CNBC and NBC News. The driver told police he was using Autopilot at the time of the collision.

The NHTSA findings are the most recent in a series of regulator and watchdog reports that have questioned the safety of Tesla's Autopilot technology, which the company has promoted as a key differentiator from other car companies.

On its website, Tesla says Autopilot is designed to reduce driver