Hi Jan I have a single bridge with 2 girder bridges, I used it with my old layout and used Atlas 3 rail track. I am sure you can use FasTrack with it. I like the look of the Atlas and it fits better on a layout since it is not as wide. I did like your design with the the along the walls, I am just turn on the entrance way with making a pull up/down access, just wondering if I the skill to make it lol
Best Charles