I lived and drove in the Phoenix metro area for many years, and there are very, very few areas that are as dense as most other cities. On top of that, the infrastructure is relatively new, the roads and lanes are nice and wide, and weather isn't a major concern almost all the time.

GP's assertion that driving in Phoenix is easier than most other places is absolutely correct.

His assertion was that it's 100x harder to drive in Detroit during winter than in Phoenix. Is that absolutely correct?

I don't dispute that Phoenix is easier to drive than San Francisco or Detroit during winter.

It's perfectly rational to debut such service in the easiest possible environment.

I just don't think that it's a fundamentally different problem to make this work elsewhere.

This technology already improved by leaps and bounds. At first those cars couldn't finish a drive in the desert, with no other traffic.

I don't have an inside knowledge on this but the fact that they are already testing the cars in more difficult areas indicates they are working on more difficult problems.

It's anyone's guess how far they are on that front.

My guess is that after launching publicly in Phoenix, it'll take less than a year to launch publicly in San Francisco.

Phoenix could easily be 100x easier than a snowy winter environment.

It is one thing to have broad streets, well marked, with multiple levels of marking, e.g., stripes, plus curbs, plus medians/sidewalks, plus trees/shrubbery. All of these well-designed and well-built modern road features cooperate to make a consistently recognizable environment. And the lack of serious weather is a big deal too.

Contrast that to a city like Detroit or Boston, where the streets are anything from modern to ancient, literally paved over the cow-paths, constantly changing with construction, lucky if the lane markings are still visible, pedestrians in all kinds of odd situations (legal and illegal) -- orders of magnitude more difficult to sort the environment. Now add snow in quantities enough to make it often difficult as an experienced human driver to figure out where you are in the lanes, and then snowbanks in odd places after it is cleared'.

Sure, it's still 4 wheels, power plant, steering wheel, roads, but two quite different games.

Going for a walk in Central Park at lunch and hiking up Denali in Alaska are also ostensibly similar activities, but in actual reality, are very different games.

>I just don't think that it's a fundamentally different problem to make this work elsewhere...

>...I don't have an inside knowledge on this...

So, based on your complete lack of knowledge on the subject, you think that the current solutions will easily extend to more difficult applications? I work in a related field (image/signal processing and ML) and I can assure you that there is no such thing as a general solution here. It is absolutely reasonable to expect that your 70% solution may simpler never work for the remaining 30% and you have to go back to the drawing board.

> Phoenix is the fifth most populous city nationwide

Yes, but that same source for population indicates that Phoenix is only the 169th most congested city in the U.S. It's suburbs are presumably even less congested.