Methods, systems, and machine-interpretable coding for causing a processor of a vehicle controller installed in a vehicle such as a rubber-tired gantry (RTG) to generate, using known position associated with a base station and signals received from a Global Navigation Satellite System (GNSS) receiver located at the base station, a satellite observation error estimate; generate, using the satellite observation error estimate and a position of vehicle determined using signals received from a GNSS receiver mounted on the vehicle, at least one control signal representing a navigation command executable by at least one control device of the vehicle; and to output the control signal for execution by the control device. Generation of control signals can include use of synchronous and asynchronous processing, ambiguity resolution processes, and as fuzzy logic and PID and other control feedback loops.