On reflection, you're right. Perhaps three taxis occupy the same road space as one bus, if they're full that might mean 15 people, compared to perhaps 30 on a s

On reflection, you're right. Perhaps three taxis occupy the same road space as one bus, if they're full that might mean 15 people, compared to perhaps 30 on a single-decker, and 60 on a double-decker bus. But still, I would say there's potential for high-occupancy taxis to play a role. In the future it may well be that the distinctions between buses, taxis and Uber-style service gets blurred. I remember reading that there are already trials in Finland for on-demand buses which dynamically alter their route to pick up and deliver passengers.