Nice topic.
Based on an editorial from several years back I opted to concentrate on what I remember as a child. I grew up almost alongside the CNJ 4 track main line and witnessed multiple CNJ commuter trains, coal drags along with some Reading, B&O, C&O and N&W equipment. I don't have the space to replicate the 4 track main but elected to sell off everything not related to early 1960's CNJ.
Layout is called the Jersey Central
A stub end 3 track staging yard in an adjoining room serves as the poor mans representation of the terminal in what is now Liberty State Park. Trains leaving that location travel to an as yet to be named junction that is part of one of the three reverse loops where it passes through Gum Stump mine. Those of you familiar with this track plan from MR in the 60's will know it. The single track main is on the lower level, the upper level holds a k line Plymouth that shuttles hoppers back and forth. The main then passes through a ceiling height mountain that serves as a partial view block from the rest of the layout. I think it makes the layout seem larger. Emerging from the tunnel it passes over a river, again a poor mans representation of the Delaware, and enters the town of Easton. Easton serves as a three track commuter station and junction dividing into the lower level return loop and an upper level loop that circles back and passes over the lower level mountain tunnel.
The town of Easton which is above the three track station has a simple loop of 027 track embedded in the street. Two MTH pcc's serve this loop, one NJT and one public service. I went with 027 because when this was constructed Super Streets did not have any turnouts other than Y's. I use manual 027 switches for care storage off of the loop.
The main layout is all gargraves with half ross and half GG switches. The upper loop is super O because I needed the 036 size, had it on hand and did not have the confidence at the time to create my own loop out of gargraves. I regret that decision but it is in place and seems to work fine.
Control is an MRC 270 watt transformer with walk around for the main and mine shuttle, trolley's are powered with a MTH z-500 brick and a power master.
TMCC is my preferred method of running but I can easily run conventional.
Ruling track radius is 042, again a regret but space limitations prevented larger. I wish I had installed 054 at least.
Scenery varies from something I might almost share to I am never going to take of picture of this ever.
There are no locomotive facilities, I felt that would take up too much space with little return. This layout is based on the concept of a stage, trains appear on stage, traverse the scene, and leave for someplace else. All yards and engine facilities live only in the imagination. The 3 track station, the mine scene, the river, and Easton all serve as distinct scenes, you really cannot see the entire layout without following the train.
Having a single track main with return loops allows a change in direction so there look of a train chasing itself does not happen. Commuter trains are 3 car max, freight trains are limited to 8 cars due to return loop capacity. Since I spent endless hours as a kid watching the CNJ commuter trains travel through Bayonne, at least until they took away the trains due to the Aldene plan. This representation works well.
Power is mostly Lionel, Atlas, WBB, diesel. I never saw steam run through town but own 3 steamers, a 4-6-4T by Kline, a 0-6-0 from weaver and a 0-4-0 from ROW.
If we ever move and this layout is taken down I hope to have the space to create a three track layout based on modular standards that can be adopted to the available space. For now this is and will be the layout.