The NHTSA will look into a total of 58 traffic safety violation incidents including 14 crashes that lead to 23 injuries. According to six reports filed by the organisation, the self-driving vehicles did not stop at intersections when the red traffic light was being flashed.

It instead, barreled into the intersection and crashed into other vehicles. Four crashes from such vehicles lead to one or more injuries, Reuters reported.

If the NHTSA detect an unreasonable safety risk to users from the vehicle during the investigation, it would pursue a recall of these vehicles.

Outside of traffic signal and wrong way violation, Tesla is also being investigated for a series of incidents, where its self-driving vehicles did not stop at railway crossings when a speeding train was going across.