For starters, Waymo reported 1 disengagement per 29,944 miles driven in 2020 to the California DMV [1], while in the talk, Karpathy implies that a Tesla being able to drive around the SF area for 2 hours without a disengagement is unusual. Note that Tesla didn't file a disengagement report because they didn't do any autonomous testing on public roads in California in 2020.

There are issues with reading too much into disengagements, but there certainly seems to be a large difference here.

[1] https://thelastdriverlicenseholder.com/2021/02/09/2020-disen...

Waymo's number for 2019 was around 11,000 miles driven per disengagement. It's been improving steadily, at a reasonably good rate.

Tesla wimps out and won't test in California, because they'd have to report.

Isn’t Waymo only driving in small HD mapped areas? Previously the were only driving within a 50 mile area of Arizona where it’s clear weather all the time.

Waymo has published detailed safety performance data of their Arizona operations: https://waymo.com/safety/performance-data

You can read their other safety whitepapers in https://waymo.com/safety

Arizona roads are also mapped to extreme precision, have very wide lanes, and are optimized for cars. Waymo has prioritized low intervention by being overly cautious and avoiding hard maneuvers (like many left turns).

That doesn't work when they scale up to any other set of normal roads, especially as density and complexity increases.

They don't avoid left turns. There are plenty of videos from Chandler, AZ of Waymo performing unprotected left turns perfectly fine.

They will always map roads to precision, whether it's Arizona or San Francisco. Why is that a problem? You should either look at their CA disengagement reports over the years or wait until they roll out a service in SF (where they've been testing heavily). That will show how safe they are in dense environments.

From what I gather, they manually mark sections as hard when the cars get stuck there, e.g. due to road work, and then their routing system chooses another route, e.g. one that avoids the left turn.

The video with the Waymo car getting stuck and taking off from the rescue team had an example of this.

I guess it makes perfect sense from a engineering perspective.