| 摘要 |
PROBLEM TO BE SOLVED: To easily, understandably and quickly perform display and retrieval of road map information and a constant and preparation of the constant by displaying only the road information of a specified data kind on a map display screen from the information of a storage means and retrieving specified node and link when the conditions of the node and the link are specified on an information input screen and an instruction of retrieval is issued. SOLUTION: A nationwide digital road map data base 20 stores node and link information as numerical data, while a map information read processing part 13 reads the data base 20 and displays a road map on a map display screen 112. A screen operation main menu 111 specifies the data kind of the data base 20 displayed on the map display screen 112 and the mode of an information input screen 113. On the screen 113, in the case of specifying node retrieval and specifying a node number or the like for instance, a symbol for indicating the node is displayed at a pertinent position on the map display screen 112. |
