Elevated 2-seat track guided motor driven wheeled PRT system with a maximum speed of ~45 kmph, vehicles coupling into train-like formations & decoupling to disperse at city ends.
Tracks laid out largely parallel to existing streets with drop off stations, 2 times the size of a regular bus stop available every 1 km. to enable 500 m comfort walk distance access.
Tandem seat autonomous driverless robotic vehicles running on elevated grade separated dedicated tracks only a little wider than the human shoulder....powered partially by solar panel arrays.
Vehicles available on demand, 24X7, enabled and activated through a contact less payment card, air-conditioned at added cost to energy like any vehicle.
A single track with vehicles carrying ~1 person cruising at 45 Kmph spaced at 50 m equates to a single urban lane of automobiles carrying ~1 person at 12Kmph spaced at 10 m - both carrying ~ 1000 persons past a point.
3 parallel tracks can be built consuming the width of this one single lane, releasing the ground space for alternate BoP low carbon safe movement channels.
For smaller dense travel demand zones or low demand suburbia, lines can be considered & installed incrementally on demand...