plan as you go

[doctorwayne]

...Do buildings come first then the railroad lays track to service them or is it really the other way around.....

For the prototype, I suspect that it's a mix of both. Some industries would already be in place before a railroad was built, and some new ones would be be built to take advantage of the opportunities afforded by the new railroad. I'd guess that the existing ones would ask to have rail service (it's my understanding that the railroad supplies the turnout(s) for connection to their track and that the industry is responsible for the siding itself, both construction and maintenance).

For my layout, I didn't have a trackplan and simply built benchwork that would fit the odd-shaped room and yet leave reasonably generous aisles. Because of the room's shape...



....I layed-out the mainline curves first, using the widest possible radii that would fit, and then connected the curves with reasonably straight track. Any space which was left could then be developed as I saw fit. (The area in grey on the picture is for a partial second level, and is currently under development.)
I still don't have a drawing of the track layout, but did manage to include 32 rail-served and fully-modelled industries on the lower level of the layout. A couple are quite large, but there are also industries not-modelled but served by industrial staging tracks - their purpose is solely to receive or ship cars....traffic generators which take up little space.

Wayne