Here's a little trick I discovered while playing Zoo Tycoon 2.
This trick allows you to place elevated path railings without the elevated path being visible.
What You Will Need:
Snowleo's CombiPatch, available here.
Raymond's Invisible Elevated Paths, available here - Registration is necessary.
You will need Zoo Tycoon 2: Endangered Species to use elevated paths
The Tutorial:
Follow the steps as described and this method should work. It works for me every time, at least!
UPDATE:
The trick will only work when the game is paused, so make sure the game is paused before you use the trick.
Thanks to Astrotom3000 for bringing this to my attention!
If it doesn't work for you, all I can suggest is you try and try again.
Watch the video closely and copy everything I do. I really can't help you any more than that!