Import road data to add it to the current model. Configure imported road data to specify desired settings such as elevation offset, and lanes forward/backward.
The definition of "right" and "left" for Lanes Forward and Backward depends on the vertex order of the underlying polyline.
Elevation offsets are used in conjunction with the Draping settings on the Source tab. You can drape a feature on the terrain and then move it 5 meters below ground level by using an elevation offset of -5.
You can use an expression to map a property from the data store to an attribute. See Use Expressions.