Improvement of three-dimensionalization method of roads and railroads in 3D Digital Japan Basic Map

Abstract. Toward the realization of the Digital Twin, nationwide 3D maps are being developed in many countries around the world. As a fundamental map covering the whole land of Japan, the Geospatial Information Authority of Japan (GSI) maintains the map called the Digital Japan Basic Map. The Digital Japan Basic Map has been prepared as 2D map information. Due to Cabinet Decisions made on 2023, GSI is required to implement 3D mapping across the whole country by FY2028. In this report, we describe the implement of 3D map in Japan, issues and improvement in three-dimensionalization method for roads and railroads, verification using MMS data, and supposed future directions.