Navigation device and method using map data correction files

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 and supplemental corrective data files. In at least one embodiment, the method includes correlating the current location with the map data, and in the event that the current location and derived map data are seemingly at odds with one another, performing at least one secondary action. In at least one embodiment, the secondary action may be the issuing of an approve/reject prompt to the user, or the automatic creation, modification or deletion of a new or pre-existing correction. In a further aspect, at least one embodiment of the invention also provides for a PND or navigation system storing an indication of a home location, and prompting a user to visit nearby locations for which corrections exist, followed by prompted or automatic confirmation or rejection thereof.