How do I lay tracks on a gradient?
Select planning mode.
You’ll need to temporarily remove tracks sections at the top and bottom of the gradient. Double-click the gradient section. The ends are marked with a blue arrow to indicate that the section is ready to snap. Click one of the ends and its arrow turns green. Now you can move this end without moving the other.
Move it in the Z plane to raise or lower it. Use the properties box if you know the distance to be moved.
Replace the moved tracks. The ends should joined correctly or nearly so. They may need to be snapped into place.
For a fuller information see this German language post. Right click and select “Translate to English” from the context menu.