There are studies on this, but most of them are paywalled.[1] The key value issue is "takeover time", where a level 3 system asks the driver to take over. Values studied are in the 5 to 7 second range.
This is marginal. Volvo was trying for a level 3 system where, if the driver did nothing, the vehicle ended up safely stopped, preferably out of traffic. That's the gold standard for level 3.
"Under German law, to be allowed to operate at Level 3 above 37 mph, vehicles will have to be able to autonomously reach a 'safe haven' such as a breakdown lane in case of an emergency."[2] Mercedes is not there yet. They claim 10-second handoff, but they really want the human back on line in 3 seconds.[3] Look away from the road for 5 seconds, and the system starts complaining.
I can’t find anything supporting “they really want the human back on line in 3 seconds” in your 3rd link. Quite the contrary:
> You’re allowed to take your hands off the steering wheel, to take your eyes off the road, and even to turn your head to the side. But you can’t take a nap.
>
> As I discovered in my short closed-course test-drive, some flexibility is built into the system. For instance, as long as you’re belted, it’s OK to look back to a child in the back seat for three to five seconds.
>
> You can push it too far, though. After consulting with the engineer in the passenger seat, I closed my eyes completely, and just eight or nine seconds later a prompt popped up asking me to confirm I was still alert. I ignored it, which soon started the 10-second countdown toward disengagement.
Human back online in three seconds is really not much different from instantaneous. Certainly not reasonable to read a book with both hands on the book and not on the steering wheel.
This is marginal. Volvo was trying for a level 3 system where, if the driver did nothing, the vehicle ended up safely stopped, preferably out of traffic. That's the gold standard for level 3.
"Under German law, to be allowed to operate at Level 3 above 37 mph, vehicles will have to be able to autonomously reach a 'safe haven' such as a breakdown lane in case of an emergency."[2] Mercedes is not there yet. They claim 10-second handoff, but they really want the human back on line in 3 seconds.[3] Look away from the road for 5 seconds, and the system starts complaining.
[1] https://www.sciencedirect.com/science/article/abs/pii/S00014...
[2] https://www.motortrend.com/reviews/mercedes-benz-drive-pilot...
[3] https://mercedes-world.com/news/mercedes-benz-level-3-drive-...