The Digital Road Map Database is a basic element of intelligent transport systems. Japan Digital Road Map Association (JDRMA) was established in 1988 to establish the standard for digital road map (DRM) and to produce a DRM database in Japan. The JDRMA started the DRM database production using 1/50,000 scale topographic maps first and is now in the process of improving the database using 1/25,000 scale topographic maps which offer more detailed and precise features. As of March 1994, the JDRMA's DRM database based on the 1/25,000 scale covers more than 50% of Japan. The JDRMA supplies the users with an updated version of the database in March every year. Car navigation is currently the largest application of DRM. There are about 20 navigation systems now on the market. About 400 thousand navigation systems had been sold till 1993. At the beginning, navigation systems were sold together with cars. Recently after-market systems are expanding its sales. Police departments, fire departments, ambulance services and taxi companies use location systems that use DRM. Significant applications of DRM are expected to come in the future in the planning and management of roads. (A)
Abstract