As a regular AutoPilot user, it does require active supervision. You need to be looking out the window as it drives you down the highway.
It detects minute levels of torque on the wheel, so resting a hand in the wheel is enough to keep it happy. If it doesn’t detect any torque on the wheel it prompts you, and you can touch the wheel or move one of the scrollwheels to let it know you’re paying attention.
> In general, it is very hard for humans to keep paying close attention to something they aren't involved in actually actively controlling
I hear this a lot without citations, and I would guess it’s not specifically studied in terms of Tesla AutoPilot.
But what I can say is that AutoPilot takes the strain away from driving and allows me to focus on higher level planning and situational awareness. I watch the cars around me, I look ahead down the road and check mirrors more frequently. AutoPilot makes driving significantly more pleasant while allowing me to be more aware of potential risks around me.
I have no doubt some people choose to disengage. But it is by no means difficult to stay engaged in monitoring the drive, or at all boring.
On the contrary, while I’ve many times “zoned out” while driving as simply maintaining position in lane is extremely tedious, I’ve never zoned out while on AutoPilot, because watching the absurd things that the drivers around you are doing never gets old.