OK indoor layout folks. I have an 8X12 portable layout in my basement that I built on 8 2X4 tables. I'm not able to build a permanent layout so constructing multiple levels usinig the old bench work methods are out. However, I'd like to ad some interest to my basic ovals and thought about building a trestle riser and a cross-over so the trains could pass over/under each other and make the layout more interesting. The problem is, this needs to be somewhat portable and not secrued to the tables. I've looked at the Aristocraft cross-over set, but wasn't sure how stable it would be. I've also thought about using foam, but this would block the view of the tracks on the back side. Can anyone offer any ideas for how to build such a trestle/crossover setup easily and portably (and cheaply)? Is the Aristo set stable enough to hold up to multiple runs of heavier trains?