There are several programs to plan and construct a model railway. And it seems you know at last one of them. One advantage of them is that they can print a list of used parts to build the model railway.
To create the layouted plan with TikZ you have to write a new code to layout the plan with TikZ. That is not easy and a lot of work (as also @MartinH said in his comment).
I personaly think it makes no sense to recreate that. Better is to use the existing program and include the result with
\includegraphics. If you have problems with the quality of the picture change the format in the planing software for saving the plan (to
.epc). If that is not possible consider to change the planing program for the model railway.