that little purple machine, politely off to the side of the path to let other's pass, with one of its arms extended as a kind of positive break, is what we in cameroi on lananara call a masterbot. they are non-a.i. robotics, psi linked and programed, which are used to build paths, tend gardens and agriculture, and even dig mines. in places so rural as to be far from the nearest track or guide-way network, they double as personal transportation. they're not fast. you'd never prefer them to something faster on rails, but they beat walking.