The National Highway Traffic Safety Administration is contradicting a claim from Tesla that the agency said Autopilot reduced crashes.

In January last year, Tesla CEO Elon Musk tweeted that an NHTSA report said Tesla crashes dropped by almost 40 percent after Autosteer was installed. The report came from a 2017 investigation of a 2016 fatality involving a driver using Autopilot. The Autosteer system is the part of the Autopilot system that keeps the driver centred in their lane.

Now, the NHTSA has said that its crash investigation “did not evaluate whether Autosteer was engaged” and “did not assess the effectiveness of this technology,” Reuters reports.

What the NHTSA is saying is that the Autopilot analysis in the 2017 report was just a “cursory comparison” of airbag deployment rates before and after Autopilot was installed. They were looking to see if models with Autosteer had higher crash rates. If that was the case, the NHTSA may have found that further investigation was needed.

SEE ALSO: NHTSA Investigating Tesla Model S ‘Autopilot’ Crash

The National Transportation Safety Board said last month that it had two other investigations ongoing for Tesla vehicles. One for a battery fire, and another for a driver who ran into his garage.

NTSB Chair Robert Sumwalt said last year that “Tesla allowed the driver to use the system outside of the environment for which it was designed and the system gave far too much leeway to the driver to divert his attention.”

That statement came as the result of a fatal crash in Florida where Autopilot was engaged.

[Source: Reuters]