The compact intersection map data for in-vehicle navigation system.

The map database is an element of primary importance for In-Vehicle Navigation System having superlative positioning accuracy and route-guidance function. This article describes a software system to create a map database. One major advantage of the Matsushita Map Database is the enlargement of intersection data used for the route-guidance function. The method used for creating enlarged maps allows accurate depiction of 45,000 intersections, as well as important additional data to be stored in its entirety on one CD-ROM disc. This paper describes the nature of the data and the algorithm used to create the enlarged intersection maps. (A)