how about creating a custom wall profile of your railing and apply it to a wall or beam (beams can be sloped along with the terrain. For site fences you are not usually seeing them up close, so depending on the scale you can elaborate fencing only where it will show. Verticals may not even be necessary depending on the scale, or columns can be paced multiplied along lengths of fences...
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"