Nice work; very realistic! :thumb:
SAL,
yes, there are specifications to module building. The track alignment is actually pretty easy to do, and there is a required 'setback' for the rails at the ends...this allows them to be connected with a simple straight piece of Atlas track. The pre-made straights are all the same length, so as long as the setback from the end is at the correct measurement, they fit right up. A little fluctuation may result in some gaps at the joints, but not enough to cause problems most of the time.
Modules and clubs are the only way some of us with small homes will ever get to run those really long trains, and it's a lot of fun (great to see others modelling work as well when we set up).