A navigation system for a vehicle generates a guide display in the form of a diagrammatic roadmap during travel on surfaces roads and in the form of a textual road-name display exclusively during travel on freeways. In addition, the navigation system has a manual reset switch which triggers the change of the display image back to the diagrammatic roadmap after freeway travel and replacement of a deduced vehicle position with the known position of a road feature at which a driver is prompted to push the reset switch.
