Abstract
Detailed road alignment data are now required to realize lane departure/curve speed warning services and other advanced ITS services and to reduce the green house gas emission from autos. However, the provision of detailed road alignment data is slow in Japan partly because of the considerable costs for collecting and updating these data. In this paper, three-dimensional road alignments, especially the lane data were estimated using the CAD drawings and the alignment of a centerline of expressways. The vertical curvelength(VCL) data did not exist and they were determined to meet the specifications of Road Alignment Ordinance. The estimated three-dimensional alignment data were compared with the five-meter-mesh DEM data of the GSI. It was found that the difference is less than 1m in most cases except specific vertical curve sections where the freedom in determining the VCL is greater.
