For the second time this month, a video has surfaced that apparently shows a Tesla driver asleep or passed out behind the wheel while the car is operating in its semi-autonomous Autopilot mode.

The video posted to Jalopnik was allegedly shot somewhere outside Las Vegas. In it, a man can be seen resting his head on the seatback with his eyes closed as the car speeds up and slows down within a lane.

Any other vehicles on the road are out of frame during the short, 18-second clip, so there is no telling how heavy the traffic was at the time of the incident. No reports have surfaced of anyone being involved in an accident in the area under similar circumstances.

Just 10 days earlier, a video of another driver in the same condition on a Southern California highway was posted to Facebook. According to Electrek, the photographer wrote in the since-deleted post that he observed the car riding along by itself for miles.

AAA this week urged the automotive industry to come up with standardized names for active driver assist systems, because it thinks brand names like Autopilot and Nissan’s ProPilot Assist give a false impression of their limited capabilities.

Tesla would not comment on the videos, but cautions drivers to stay alert when using Autopilot. If it detects that a driver is not paying attention, through sensors in the steering wheel, it is supposed to warn them with lights and sounds before slowly deactivating itself.

In the Southern California video, the driver’s hand does appear to be on the wheel.

These sorts of reports have come up several times before. In December, a driver was cited for drunk driving after highway patrol officers spotted him passed out in the driver’s seat, followed his car for about seven miles and then pulled in front of it and slowed down, hoping it was in Autopilot mode and would come to a stop to avoid a collision.

It did, but it was not immediately clear why it hadn’t already deactivated on its own. Tesla CEO Elon Musk tweeted at the time that he was “looking into what happened here,” but never made an announcement on his findings.