Taxis are expensive, principally because you have to pay the driver to wait for a job, drive to you, and then drive you to your destination.
It's a terribly inefficient business model, is it not?
Well here's another model. A teenager drives to you, logs off the car (which alerts you that your car has arrived), pulls his scooter out of the boot, puts on his helmet, and then looks at the app on his phone which tells him exactly where to go to deliver the next vehicle...
His scooter runs from 30 to 50 km/h.
He spends very little time waiting around - and spends no time driving you anywhere.
In a conventional taxi your fare might cover, say, 50 minutes professional labour. In a Mevo + Scooter system it could be more like 5 minutes.
But you've got a broken leg and can't drive? Click 'taxi service' on the app, and the scooter guy will then become your taxi driver. That will cost about the same as Uber, or maybe a little less.
But you feel like going for a walk and you've got some time to burn? Click the 'pick-up' option on the app, and the system will reserve the nearest available Mevo car, based on the time you want to pick it up. This will obviously be the cheapest option of all.
Okay. So what happens when the system expands from growing demand, so there's typically at least one ready-to-go Mevo car sitting on every street? The pick-up option then becomes most popular because it's always an easy walk. The system then becomes exceptionally efficient.
Most of the Mevo cars can be single-seat Twizy cars [see here], matching real commuter demand. They will be electric and typically very small and efficient. Many of the Mevo cars operating in peak-time will include range-extenders (small petrol-electric generators) to ensure range is never an issue.
The final result?
You have a system that does everything that a hire car, Uber, and a Taxi does...only much, much cheaper.
Commercial law suggests I've described an inevitability? I would hope so, but governments (and their backers) are always the wild card...
Though I believe politics has most likely suppressed driverless implementation (see here), I don't know if the Mevo model I've suggested could be suppressed. It's not driverless so the excuses to regulate it away would be hard to find.
Externalities? Think of the parking relief and reduction in traffic noise, too. Very nice. Especially in places like my home city, Wellington, New Zealand.