A method to fuse two kinds of digital road maps

The acquisition of digital road maps is essential for automobile navigation. Digital road maps are used in Japan by the Digital Road Map Association (DRMA) based on 1/25,000 map. The digital map, however, is unsuitable for town driving. In this situation a more detailed digital road map is requested by the users. To get a detailed digital road map from a paper map is a very expensive operation. We proposed a new method to obtain a more precise digital road map using a more detailed general purpose digital map which has already been published. However, using this digital map directly for auto-navigation is impossible. The method we propose in this paper obtains more detailed road network data from the 1/10,000 map and from the DRMA data.