trains will ALWAYS try to be one signal behind another, which makes spacing a difficult task. Too many signals over the line, and the trains will be too close together. Not enough signals and they might wait too long on one another. I’d really like to see the trains space out alot automatically if you have a double-track setup with alot of signals on both sides, but i don’t think we’ll see this. It is possible to space out trains but it is difficult to do.
and vehicle maintenance appears to increase infinitely, so eventually it becomes a no-brainer to upgrade