Would be cool to have additional signaling systems

Most importantly, how cool would it be to have CBTC (Communications-based Train Control)?

It would be really nice to have this, or some ERTMS level 2 or 3, for a super high cost so it makes it meaningful.

And some network priority tool, so you can have a main line with absolute priority so we don't make a 200kmh Train stop for another one joining the line.

Idk, just thinking outloud...