# 12da roads

12da files can contain one or more alignments or super alignments. The Trimble Access Roads software can work with both alignment types. 12da files are created from 12d Model software.

12da files do not contain information allowing for the grouping of strings into a road surface, and so a road surface is not displayed in the map like other road formats.

The Roads software treats all road distances, including station and offset values, as grid distances. If a ground coordinate system is defined in the job, the grid coordinates are, in effect, also ground coordinates.