This is great data. I'm curious what will happen with all of the talent that recently left Google, including various startups for self-driving cars. That said, Google is doing better than I thought. Kudos to them.

Any idea how to benchmark this against humans quantitatively? Also, any idea how trivial or significant a disengagement is?

Google's "perfect" record on freeways lends credence to my theory that trucks are just a few years away from being fully automated. I actually suspect the laws will trail the technology there.