| 摘要 |
PURPOSE:To provide an optimum route from a start point other than already prepared nodes of map data used for route search to a destination so that it is easily understood for a driver. CONSTITUTION:A map data storage means 3, a register point input means 2 which inputs at least the start point and the destination to register them on a map, a conversion data generating means which reads out road network data on plural maps from a map data storage means 3 and converts them into a data structure of plural hierarchies provided with node data and link data hierarchized by road network classifications, a land mark register means which additionally registers register points, which are inputted and registered by the register point input means 2, in road network data of the lowest hierarchy as land marks in the case of disaccord between these register points and nodes on the map, an optimum route search means which calculates an optimum route from the start point to at least the destination based on registered hierarchized road network data, and a route display means 5 which displays the optimum route obtained by the optimum road search means together with register land marks are provided. |
