Tesla's largest-ever recall. Over 2 million vehicles require autopilot safety updates amid heightened accident risk

Following a two-year investigation and numerous reports of incidents, the US National Highway Traffic Safety Administration (NHTSA) determined that Tesla's autopilot driver attention control systems are inadequate, Reuters reports.

The NHTSA analyzed 956 incidents involving 23 fatalities among users of the autopilot system. According to the agency, this system has a heightened risk of accidents.

The agency stressed that safety systems must consider that drivers often over-rely on technology. Although Tesla's autopilot doesn't make cars autonomous or self-driving, drivers must nevertheless maintain their alertness and drive responsibly at all times, despite the use of such technology.

Although Tesla disagrees with the ruling, it has decided to update its autopilot safety systems. This decision marks Tesla's biggest recall effort to date, encompassing over 2.03 million S, X, 3, and Y models, from 2012 onwards, according to Reuters. Owners won't need to take their vehicles anywhere, as updates can be applied at home.

As reported by Reuters, the software update will introduce "extra control elements and urges for those already in the affected vehicles so that drivers are more attentive and responsible when the autopilot is activated".

There will be more noticeable alerts, with the autopilot function becoming easier to enable or disable, and additional features once the autopilot is switched on. As Tesla noted, should a driver continue to ignore the checks, autopilot use will be deactivated.

However, the NHTSA is not concluding the case. It will carry on investigating and assessing the full impact of the update on driver safety.