A really tough problem with signals

[llkko]

I´m basically building a track layout with 2 tracks + an overtaking track in the middle (as seen in the attached image). It works fine most of the time, but it sometimes fails.

What I would like to do:
1. Trains stay on their main tracks, they go to the overtaking track only if the next section of the main track is occupied.
2. Trains go back to their main track only if their adjacent main track section is not occupied.
3 (bonus). If the track section in front and the adjacent track are occupied, the train stops.

I´m not good with signals, I use PBS basically for everything, so this problem absolutely stumped me. Is there any way to make it work?

[LaChupacabra]

The train from the screenshot chose the external route because there are inverted signals on the central one - they are necessary for trains to prefer external routes, so don't remove them. He would have taken the middle route if another train had taken the outer track before him. This did not happen and he took the first of this line.

Unfortunately, with this track layout nothing can be done by just changing the signaling. You could use checkpoints, but sooner or later somewhere, one train would block the route to another.

Theoretically, priority can be given to railroad routes using pre-signals, but this would not work well in this case. Perhaps setting restrictions on signals from the JGR version could help, but I don't know - I've never used this option.

[Alberth]

What I generally found is that the best and simplest solution is to have parallel tracks without option to switch between tracks. At the point where a decision needs to be made which direction to go, you allow all tracks in all directions. Trains do take predecessors into account if you don't use a very short signal block length, so they will generally pick a more empty line from the next bunch of parallel tracks.