after my previously unsuccessful attempt on making a train track around the room (will have a short write up on this sometimes later), I moved to another house, and have a "real" lego room (instead of the lego section in my bedroom), the first thing I did is to start building the track.

this is the smaller room of the 4 bedrooms, about 11 ft by 10 ft, has a small window and a closet that was converted to work bench and shelves, which originally I thought would be a great corner for a train yard. the room layout looks like this (not to scale):

I planned to have 6" shelf because that's the minimum width for a curve track to turn 90 degree, and still have some room for a thin (2-4 studs) 2D buildings that I plan to build along trackside. also weight is an important issue because I do not want to use shelf bracket (they come in minimum size of 6" and are kind of big). I ended up using the metal bracket that you use to connect wood in 90 degree angle, the same type I used for my previous train track attempt, which works out okay.

the 6" shelf turned out to be 5.5" in width (lumber scale) but it's the cheapest lumber I can find (they are like $3 per 10'), 5.5" is acceptable, I think.

for the closet space, the original plan was to turn the top level (track level) into a train yard or turn around point, and use the lower level as storage shelves for all the lego I got, and the bench as a small computer desk so I can do some stuff on the computer in the lego room as well. The track would run just above the door frame so that part of the track can be supported by the door frame, and since the track would be pretty sturdy, I installed two lights under the shelves.

I didnt bother painting the shelves, but I also want to make sure the shelves are easy to clean (the old shelves have dust 'grid' on them after all these years) so I put a cover of clear contact paper on the surface. it looked great (makes the shelf a bit shiny).
the train yard turns out to be not a very good idea, for one, it's too far up that I can not reach it easily, and it is not big enough to make a circle or any sort of meaningful turn offs.
so I converted it back to be storage area, and the others remain the same:

because the change in shelf width, half of the turn will be suspended outside the shelves so I can still have enough room for the 'buildings'. the Santa Fe SuperChief makes a good demo train:

so that was it, for now, this has been a fun project, and I'm still in the process of re-arranging the furnitures in the lego room and putting things in the right(tm) place.
I have not started building stuff alongside the track yet, I need to do that sometimes.