Looks "like a plan"
What will your radii going to be? Don't think "how small a radius" think "how big a radius" can I fit (I would recommend 072 min, but you may not have the space). Do you have room for a Turntable? I recently installed an Atlas TT and am having loads of fun with it.
Although, you don't need a TT. I've been doing research on the Norfolk & Portsmouth Belt Line and the book I have says their engines spent greater than 60% of their time going backwards!