For an externally powered Chalopede, a similar pair of foot operated treadles can be used to control the extent and rate of individual movement of the rewheels.
The possibilities are back and forth (so that the Chalopede can be reversed) and differential between left and right, which is transferred to the inner and outer rewheel feet, in order to turn the Chalopede.
As this is not an obvious feature of this design, made possible by the modular nature of a rewheel, perhaps it is necessary to point to the completely rigid nature of a Chalopede chassis, that is in fact the framework of the entire vehicle. It does not call for either an adjustable camber, or for a differential between inner and outer sides of the rewheels, that traditional wheeled vehicles must have, in order to minimise wear and tear from ‘slip’.
In that sense, this is an inherent design and engineering improvement over commonplace wheeled vehicles.