One of the most confusing things regarding using Revit as a tool for modeling infrastructure or civil elements, such as bridges, box culverts, etc, is the limitation that you can not import easily a georeferenced 3D polyline and use it directly as a path for the model-in-place family. You have to work with a lot of weird and inaccurate workarounds and you do not succeed most of the times. You can not define in Revit a family or better yet a model-in-place family that follows a path without twisting/rotating or respecting two or more line targets. it simply does not let your blend profiles stay perpendicular on the path or guidelines/targets of the profile. another problem is a big one that in most confusing ways the parameters in the sweep or blended profiles do not update, and that's results in a lot of frustrations and losing several workhours and restarting whole the process because simply one tiny parameter did not update and the family do not join to other elements.
