There is an issue when we try to use an offset polyline as a Horizontal Target.
The offset polyline takes the same ID that the original polyline.
For example, if I use the original polyline as a Horizontal target for the "Lane" subassembly, this poyline is called "polyline-34"
Then, if I add the offset polyline as a Horizontal target for the "shoulder" subassembly, this polyline is also called "polyline-34".
In this case, the horizontal target for the shoulder, doesn´t work fine because it is pointing to the same polyline.
So, when we do an offset polyline, the new polyline should have a new ID automatically for Civil 3D.
This means that I have to draw a new polyline on the offset polyline and use this new polyline as a Horitonzal target for the shoulder subassembly. It´s really stupid.