"I think this guy is passed out in his Tesla," said Seth Blake, who was driving from Anaheim to Los Angeles with his fiancé, who shot the video.
Blake says the man appeared to sleep for about 10 minutes and during that time, woke up once, looked around, and went back to sleep.
Tesla would not comment on the video, but says autopilot is only intended for use with fully attentive drivers who have their hands on the wheel.