Tesla investigation deepens after more than a dozen US 'Autopilot' crashes

US federal regulators are deepening their investigation into Tesla's Autopilot function after more than a dozen Tesla cars crashed into parked first-responder vehicles over a period of four years. The National Highway Traffic Safety Administration (NHTSA) said on Thursday it was upgrading its preliminary investigation, which launched last August, to an "engineering analysis", which is taken before the agency determines a recall. The investigation covers all four Tesla vehicles – Models Y, X, S and 3 – representing about 830,000 vehicles that have been sold in the US. The investigation is focused on Tesla's Autopilot feature, which is supposed to help drivers navigate roads through artificial intelligence, which detects other vehicles. The company instructs drivers to pay attention to the road and keep their hands on the steering wheel while using Autopilot, though some drivers have used Autopilot drunk or sitting in the backseat of the car.