Sadly, this blueprint is no longer functional: being "cheated" together with too-sharp rail turns, the switches don't link together properly, and that breaks pathfinding. A shame, as it's a beautiful, elegant and compact design, but I made the mistake of building quite a large rail network around this blueprint before realizing my trains couldn't path through the roundabouts.

This is so much more compact than by using the standard layout for roundabouts, thank you!