Since, I've been messing with layouts, here is one that I built for my brother 25 years ago. The pic doesn't reflect it, but it's an over/under where the outer loop on the right crosses over the inner loop. The only difference is I modeled this one to start a gradual grade (~1%) in the sidings on the left to get the rest of the grade down to 3%. In the original, we started the grade after the last switch on the bottom which resulted in a 4+% grade.
taylor by copperleaf, on Flickr
taylor by copperleaf, on Flickr