Associated Press contributed to this report. A video has emerged on Twitter of a man asleep at the wheel of a car as it drove along a highway in Massachusetts at around 55 to 60 mph . Tesla vehicles have an autopilot feature that takes over many of the driver functions . A driver - monitoring system allows drivers to stay alert and can stop autopilot if the warnings are ignored .
A video has emerged on Twitter of a man asleep at the wheel of a car as it drove along a highway in Massachusetts at around 55 to 60 mph . Tesla vehicles have an autopilot feature that takes over many of the driver functions . A driver - monitoring system allows drivers to stay alert and can stop autopilot if the warnings are ignored .