Sure! And that's a legitimate service to offer to some people. But that's part of the giant gap between true autonomous taxis and what Waymo has even claimed they're doing.

I think the difference is important because people here frequently assume that true autonomous taxis will be here in short order. In contrast to experts who believe it is likely to be a decade or two away. E.g.: http://rodneybrooks.com/my-dated-predictions/

You are conflating two concepts. One is the ability to complete 100% of any ride and react to a kid running into the street, etc. The second is to satisfy 100% of current taxi service like rural areas or dirt roads.

100% safety on 90% of possible trips is a damn good business, let the taxis take the other 10%. That is “autonomous taxis are here.” 90% safety on 100% if possible trips is how you kill people.

Hahaha, also, 100% safety on 90% of trips sounds like the kinda thing Google would do, and 90% safety sounds like the kinda thing Uber would do.

Maybe someone is conflating those things; I'm not.

I agree that doing 90% of possible trips could be a good business. But it's not the same thing as true autonomous taxis. And we don't have any idea what the actual percentage of achievable trips is. 20% would still be a good business if you pick the right 20%, but it's no threat to Lyft.

20% of their market gone in a puff of smoke is no threat to Lyft?

It wouldn't be a puff; it would happen over a significant period, during which their other business would still presumably be growing. And it would give Lyft substantial time to adapt competitively. So no, I don't believe it's a threat.

This is a great point. Not even humans do 100% of possible trips if they aren’t confident drivers, especially in bad conditions.

Might as well take a bigger discount and use BART.

This does bring up an interesting question though -- does self driving doom mass transit? The answer is no -- the real ultimate benefit of mass transit that taxis can never replicate is _thoroughput_ in a dense area. Articulated buses or light or heavy rail are the only way you could ever service an area like Manhattan, because even with high occupancy, using just sedans would require the building of like, literally 50 more highways. A single lane of train/bus can do the work of dozens of car lanes and nothing can change that physical law.

Self driving buses will reduce the price slightly though. And importantly, people today often drive because of the "last mile" problem. Driverless taxi on the other hand, may make it much easier to connect to mass transit seamlessly. You could even connect more than once. I could get from suburban Queens to the suburbs of Philadelphia by taking a taxi to the train station, a train that is faster than cars due to traffic, then another taxi on the other end, seamlessly. Actually I can do that today, it will just be cheaper, that's all. So more people will do it.

> the real ultimate benefit of mass transit that taxis can never replicate is _thoroughput_ in a dense area

But what if in the far future people stop owning cars and so everyone is hailing a self driving car? Perhaps then there would be enough people that you would almost always carpool? Would buses still be necessary then? I'm sure they'd still make sense in some cases but I can also see some bus stops being replaced

Yes, they still would in places like Manhattan and Tokyo, but you're right that they wouldn't be necessary in many other high but still not super high density places.

Even assuming 4 people to a sedan, the space needed for the engine and the safe following distance makes the density very low compared to a bus/train that is long and can have people standing packed in.

4 people to a sedan only gives you a factor of 4 improvement, which is just not enough for places like Manhattan or Tokyo. They would still need to build a dozen down from like 50.

You can't live anywhere near a BART station, let alone a few hundred feet, without losing any sort of discount with mass transit... Not to mention the vast majority of the metropolitan Bay Area is miles away from BART.

There's a big difference between 100ft to the nearest road vs 5 miles to the BART station. Last mile transportation is important, even if constrained to fully mapped roads.