Modular Catwalks

With muiti-level map support coming, it'd be cool to have modular catwalks like how pipes work right now. Making overhead walkways for warehouses would be pretty cool.
The reason I think they should be a modular object instead of a terrain is that in most warehouse settings, catwalks also just sit slightly over the ground for any area that has enough pipes or other materials that could be a trip hazard. Making them modular instead of a floor would allow for multiple uses.