Berlin had an on demand ride sharing shuttle service, called BerlKönig, that has been run by Berlin's public transport provider BVG. Unfortunately it was recently discontinued, but apparently the BVG is planning a new on demand service.
BerlKönig was automatically following routes that would optimize for a higher load factor.
For me it was the best option for certain scenarios.
Cities have the demand to support real transit which is vastly more cost and energy efficient. They have congestion which isn't helped much by shuttles compared to a bus or other high capacity transit. Congestion also slows the shuttle down so you need more shuttles and more depots. They also have more destinations at cyclable distances.
Paratransit is for mobility for theose who can't drive in areas that can't justify a train or enough buses for a <1hr max wait time. It needs a larger per km subsidy to be affordable.
> They have congestion which isn't helped much by shuttles compared to a bus or other high capacity transit
Multiple simultaneously driving taxis can be replaced by one shuttle van at times or for routes where large busses would run mostly empty, because they lack flexibility.
Yeah, if you need coverage shuttles are great albeit at a high marginal cost per trip. If you need capacity then they don't really work. A city will spend more on shuttles than they would on a network extensive and well designed enough to get good utilization.
I guess they are useful in some US cities as a stepping stone where there are massive political and legislative barriers to building a functional city.
But I found them useful in Berlin (see my other comment in this thread) and Berlin already has one of the best public transport networks in the world, I think. For me they were just closing the gap between taxi and public transport. In terms of use cases and in terms of pricing.
Point. I guess I was more responding with the use case of an alternative to mass transit.
I agree that filling the gaps that busses or trains can't is a great use case, and I guess that my point about small towns was just one example of a gap.
BerlKönig was automatically following routes that would optimize for a higher load factor.
For me it was the best option for certain scenarios.