Merging My Wants Into A Single Layout

I have been wanting to set up an HO layout to include CSX Transportation and Norfolk Southern Railway and I have been at a loss as to how I would do that.

After some careful consideration I have decided to include those two lines in my grand kids layout currently they have a BNSF layout, so I felt I could expand that layout to include 3 mainline tracks to incorporate the other two lines.

This way I will have a layout that displays lines that service the East and West sides of the country. I can hardly wait to get started. The inner loop will be the BNSF Railway, as that much is already up and running. I use 18 inch radius track on the curves for the inner loop. The middle loop is the next thing I will work on and I figure 22 inch radius track will work out well. I haven't decided what line I will put on that loop yet. It will most likely be CSX. That would leave the Norfolk Southern Railway for the outer loop. I will most likely use a 26 inch radius on that loop.

Proposed layout Plan