You can already look at Uber pool, which is a direct tradeoff between cost and speed.
The '03 Crown Vic has long since paid off it's capital costs and the cab company gets to blame the driver if things go far enough south for lawyers to get involved.
Until some mythical future where self driving cars are so good and common that the "progressive" states start providing financial disincentives for people to operate their own vehicles (which would be a pretty major about face the vast majority of all transportation and infrastructure related regulation to date) I don't see where the driver-less taxi has a cost advantage in the foreseeable future. Your insurance premium is in large part based on the presence of everyone else around you.
It doesn't matter if the cars cost 100K, the driver wages still are larger than the capital costs.
>Especially if I get the huge benefit of not having to drive.
>Driving risky really doesnt speed up your commute very much.
A car behaving will be like a student driver (or delivery truck) at every intersection at which it needs to pull into traffic could easily double or triple your commute time depending on your commute.
Pulling out into traffic should be something that a driver-less car can be much better at. If it isn't at least as good as the average perspective customer people won't buy it.
I would say this is particularly critical metric for taxi fleets since they do a lot of driving on city side streets. People will take taxi with the human if it's faster.