We have to be careful that taxi or vehicle is not the only transportation mode to be able to apply Uber system.
In South East Asia and South Asia, it's also common to use canal, river, or sea by boat. But, I don't think that all of the boats in that area should introduce Uber system. I'm proposing that boat routes carrying many passengers everyday to an extent must be operated by public sectors and by timetable basis. Otherwise, there would be a chance to install Uber system.