The National Highway Traffic Safety Administration (NHTSA) is re-investigating Tesla's Autopilot driver-assistance system over concerns that a previous recall did not address key safety concerns. The agency previously conducted a probe over the course of three years to determine whether Autopilot was to blame for traffic incidents. It concluded that the system did not include features that kept drivers engaged on the road, resulting in inattention. Tesla recalled the software in December, updating the software of more than 2 million vehicles to comply with the NHTSA. However, the administration says that some of the concerns outlined in its original investigation were left unaddressed by the electric vehicle maker's update. In addition to...