> San Francisco, San Jose, Los Angeles, Austin, and Phoenix are ~10% of US population.

Surely you're describing metro areas? There's no way those five cities add up to 34 million people within city limits, given that none of them have 6 million people.

The MSAs added up to 27 million based on the 2020 census, so "close enough". https://en.wikipedia.org/wiki/Metropolitan_statistical_area

That said, Waymo's service areas are nowhere close to covering the full MSAs: https://support.google.com/waymo/answer/9059119?hl=en

- SF doesn't cover East Bay (two thirds of the MSA by population).

- Silicon Valley doesn't cover San Jose, and barely reaches into Sunnyvale (basically just covering the Google Moffett Park office buildings).

- The Phoenix area is missing most of the densest parts of Phoenix itself, as well as anything north / west of the city.

- Los Angeles doesn't even come close to covering the city, much less the rest of LA County or any of Orange County. (Maybe 2-3 million out of 13, from just eyeballing the region.)

On Uber (https://support.google.com/waymo/answer/16011725?hl=en) there's also Atlanta (which looks like it actually has very nice coverage, other than the western half of the city) and Austin (again focused on downtown / commercial districts) which help drive up the numbers.

The population that's had opportunity to see Waymo in the wild is probably higher because they're testing in quite a few cities now (a sibling commenter mentions NYC, for instance).