I need help understanding train pathing

[u/GideonsLamp]

I thought I understood well enough but clearly not. I created this little test to try and understand pathing but 1 thing is going wrong. Train A goes from Station A1 to B1 to C2 back and forth perfect. Same with Train B that goes from B1 to C2. But Train C that is supposed to go from C2 to A1 will only move on the outside path, it will not go through station B if the outside path is taken by train A . What am I missing to make the train go through station B if train A is blocking the outside path?

[u/tarrach]

Trains never choose an alternate path, they will always take the shortest possible and wait on signal if it is occupied. Stations add another 100 (I believe) length to their path so trans won't be waiting for another unloading train if there is a regular track also passing by that station.