Took some time off from working out in the heat now that the garage has been rearranged. I had planned on looking for lumber yesterday, but found out too late that the yard I wanted to check out closes at noon on Saturday and is not open on Sunday. I'm torn between buying 1x lumber in 8' lengths and ripping 3/4" plywood for the framing. I figure I need about 22 boards and the only straight boards I saw at Lowe's was Poplar at over $15 each or over $330. The Oak and Maple plywood sheets are $50 each and I'd only need 2 for quite a savings with which I can buy a pocket hole jig. 
Anyway, we were watching our granddaughter, so I played around with my design a bit. I came up with an alternative I kind of like and would appreciate some comments.
What I did was change the outer and inner loops going across the angled connecting section so they cross over each other. The main level is now at a 3" elevation while the yellow track at the connection is at 0" elevation and the blue track is at 7" elevation. Those are rises of 3" & 4" and grades of 2.3% & 3.2%. As you can see in the 3D photo, I end up with 3 elevations where trains can pass each.
I also moved the upper leg down and over to the left 4" (didn't change the baseboard) so the trains will clear a 4-outlet box on the wall right in the middle at layout height. This will increase the 3.2% grade for that leg to 3.4%. Looking at the photo now, I see I really didn't need to move it over, just down.
This light green rectangles on the left are 18x24 cabinets and at the top are 18x36 shelving units. I moved the shelving units so the trains will clear the poles. The cabinet on the bottom opens toward the top, so I'll have fairly easy access. The others open toward the bottom, but they will be 6" from the edge for easy access.
