Here is a simple Kato Unitrack DC layout with three separate lanes. Two double crossover tracks enable switching between all lanes. Two PRR engines split the passenger cars of the Broadway Limited. At one time the Broadway Limited used electric GG1 engines for part of the trip and then switched to diesel engines for the remainder of the New York-Chicago run. This layout uses a GG1 for half of the cars and an EMD E8A diesel for the rest. The SCARM layout file is linked at the bottom.
I think this is the limit for a 4 x 8 layout. I have more than 169 feet of track in this layout. It’s all Kato Unitrack DC with three separate tracks. On each edge there are nine lanes with a working turnout. That’s a total of ten lanes on each side of the layout. A graphic and link to the layout are below.
I change my layout often. Nothing is permanent. I purchased three pieces of pegboard and use those as a base. They offer a good flexibility in how large I can arrange my layout and are very inexpensive. My last layout was 4’x 10′ but this week we need a little extra room so I chopped two feet off the layout and used the extra piece of pegboard as a second layer on top of the 4′ x 8′ layout.
I picked up a piece of green felt at Hobby Lobby. That lays on top of the pegboard to give it a slightly more realistic look. It was hot when I recorded this and the ceiling fan was running. You will notice it blowing the felt on the upper deck. If this were a permanent layout, I would glue all that down, but next week, it will be used in a different layout.
I picked up some Lego knockoff base plates and used those for the long ramps. Those work great and were inexpensive. I also found a bag of 1/160 scale cars to add to the layout for more realism. I tried making a few Lego buildings to match. Those will get better.