A video of a driver appearing to sleep whilst at the wheel of a Tesla has raised eyebrows in the US.
The footage, filmed on a busy toll road in Massachusetts, is the latest of a number of sightings of travellers apparently getting some shut eye while their Tesla vehicles are on auto-pilot – a feature which allows the vehicle to steer, accelerate and brake automatically in a single lane.
The clip from Massachusetts Turnpike in Newton, filmed and shared by Twitter user Dakota Randall, shows the driver with their head lolled forward while their passenger also appears to sleep beside them.
A statement from Tesla accused some of the videos of being "hoaxes", assuring that drivers are reminded by their vehicles to "stay engaged" by warnings received every 30 seconds if their hands are not detected on the steering wheel.
However, Mr Randall responded to the statement, tweeting: "This was no hoax, at least not on my part. Maybe the people in the car were faking being asleep, but I'm sceptical.
"I just saw something weird on the highway and recorded it. Nothing revolutionary."
Mr Randall said he did not call the police on the car, which was travelling 55 to 60mph, but state police said they are aware of his video.
A similar video filmed in August in Los Angeles, California, shows another resting driver travelling down the middle lane of a busy interstate highway.
The recent nature of auto-pilot features in vehicles mean laws in many US states are yet to catch up to specifically tackle the issue of sleeping at the wheel.
However, in California for example, while there is not a particular law about sleeping while in the driver's seat of an autonomous vehicle, police have powers to ensure drivers are not threatening the safety of themselves and others.
The statement from Tesla stated: "Many of these videos appear to be dangerous pranks or hoaxes.
"Tesla owners have driven billions of miles using Autopilot, and data from our quarterly Vehicle Safety Report indicates that drivers using Autopilot experience fewer accidents than those operating without assistance."