Abstract: A navigation system includes a display control for controlling a display monitor on which a road map and a trace of the vehicle position are to be displayed. The navigation system also includes means for detecting when the vehicle reaches a known point on a preset route. The display control is responsive to detection of the vehicle reaching the known point to erase the displayed trace and set the vehicle position to that of the corresponding known point on the displayed map.

Abstract: A navigation system and method for guiding a vehicle along a selected route of travel to a destination from a start point using a display unit. In the navigation system, a registered intersection nearest to the present position of the vehicle, present on the set route of travel and registered in a roadmap data, is used as the first intersection on the route of travel through which the vehicle is to pass. The vehicle can be guided toward the first intersection and if the driver manually triggers the system upon reaching the first intersection, the guidance process for the selected route can begin. Otherwise, the system again checks to see which of the registered intersections is closest to the vehicle, and the above process is repeated.

Abstract: 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.