Probably better than the time I took a SuperShuttle to SFO and the driver fell asleep, several times. He had a app on a phone thing to keep him awake that would beep and he would wake up, press the button, and sometimes go right back to sleep on the highway.

If the Tesla self-driving is decent, the safety driver has the very difficult for a human job of being engaged to takeover a task, but not having to do it very often. No wonder they're asleep, but the ride should probably end and a replacement come out when the driver attention detection goes off, especially if more than once.