A method of operating a PND or navigation system is described, together with a PND or navigation system for performing such a method. The PND or navigation system includes memory storing map data consisting of base map data files, a display, GPS signal reception and processing device, such together forming a basis for navigation, route guidance, and map information display. In at least one embodiment, the method includes correlating the current location with the map data to derive map-specific parameters for that location and comparing the map-specific parameters with a motion-specific parameter, a vehicle-specific parameter, or the current location to determine whether the current location, motion or vehicle-related characteristic is permissible or appropriate therefore; and in the event that the current location, motion, or vehicle-related characteristic and derived map-specific parameter are seemingly at odds with one another, performing at least one secondary action. The secondary action may include but is not limited to the issuing of an approve / reject prompt to the user, or the automatic creation, modification or deletion of a new or pre-existing correction.