Stein: I really like that design. Would you mind if I used it to try out a full track plan?
Feel free to extract whatever ideas you deem worth keeping, and to fold, spindle and mutilate the rest to your heart's desire.
The only thing I wish it had was more levels of visible/scenic area. I might try to make it a multi deck so I don't have to put double mains in. Maybe.
There might not be enough room to get good separation for the levels.
In principle, both turn back loops could contain helices (helixes?), to help increase vertical separation between two decks. Just make sure the lowest level is not so low that it gets back breaking to crawl under the table and into the helix if necessary.
The access hole can be a little smaller because there is no wall on the west side.
Of course - slipped my mind. So you could have an easy/short duck under on that side. That's good - also makes it easier to potentially put a helix here - ducking under something 4" wide is considerably easier to duck under 2-3 feet of layout.
Smile,
Stein