Patent ID: 7839306

Claim:
A map display method for detecting the present position of a vehicle and displaying a road map including a vehicle position mark indicating the present position of the vehicle and a guide route along which the vehicle runs, comprising the steps of: preparing a summarized map indicating the guide route with a summarization degree corresponding to a distance from the present vehicle position to a destination or a running speed of the vehicle; displaying the summarized map thus prepared on a display screen; and giving priorities to roads including each road traversed along the guide route, at least one main road and branch roads in that order in the summarized map; storing an ID for identifying road data for each of the roads being given priorities, categories indicating road types for the roads, and the priorities set for the roads in a table, wherein the priorities in said table set for the roads traversed along the guide route and crossing roads intersecting with the guide route in the main road and the branch roads are changed in accordance with a change in the guide route and the crossing roads existing in an area displayed in the summarized map due to a change in the present position and the running speed of the vehicle, wherein the summarized map is prepared by selecting at least one road on the guide route and at least one road of the crossing roads from the roads based on the changed priorities, and wherein each of the number of objects displayed in the display screen and the ratio of the occupied area of the displayed objects to the area of the display screen is changeable in accordance with the running speed of the vehicle by using the changing priorities.