DIGITAL MAP POSITION INFORMATION COMMUNICATION METHOD, PROGRAM FOR EXECUTING THE SAME, PROGRAM PRODUCT THEREFOR, SYSTEM THEREFOR, AND APPARATUS THEREFOR

摘要

A transmitter transmits road geometry data of a subject road (101) to be informed as well as branch geometry data of a branch (20) with which the subject road (101) intersects or to which the subject road (101) branches. A receiver refers to this branch (20) to determine, on its own digital map, the subject road (101). According to this method, information indicative of the geometries of branching roads and intersecting roads, which may cause erroneous positional determinations, is given as branch geometry data to the receiver, whereby the receiver can avoid any erroneous positional determinations leading to such branching or intersecting roads. The branch geometry (20) allows the subject road (101) and a parallel road to be distinguish from each other, and also allows a deviation in the lengthwise direction of the subject road (101) to be noticed, whereby it is also possible to prevent occurrence of any erroneous positional determination leading to the parallel road or related to the lengthwise direction of the subject road (101).