In Finland, actually. The Kutsuplus is Helsinki's groundbreaking mass transit hybrid program that lets riders choose their own routes, pay for fares on their phones, and summon their own buses. It's a pretty interesting concept. With a ten minute lead time, you summon a Kutsuplus bus to a stop using the official app, just as you'd call a livery cab on Uber. Each minibus in the fleet seats at least nine people, and there's room for baby carriages and bikes.
You can call your own private Kutsuplus, but if you share the ride, you share the costs—it's about half the price of a cab fare, and a dollar or two more expensive than old school bus transit. You can then pick your own stop, also using the app.