I tried to get a few trains ride on a rail in both directions through the establishment of the railway ring and waiting areas. But when I tried to place Rail Signals I noticed a minor bug - when I put Signals on diagonal rails they did not find their "brothers" on the other side of rails and create little path's blocks, that did not allow trains to move automatically between stations.
Only one Rail Signal
Two-way Rail Signal
Savegame - https://www.dropbox.com/s/h2186iwz5c2wqjv/bug_.zip?dl=0P.S I'm not an English speaker, I am sorry for any errors.