[Csantucci]

In activity mode I'm trying to create an AI train (let's call it train 1) in front of another (already created) AI train (let's call it train 2). There are at least 4 signals in between and I have checked that, at the moment I create train 1, train 2 has at least a red signal between itself and train 1. I would suppose that in such a case train 1 could be created (why not?). Instead it is not, and it is created only when train 2 passes the position where train 1 has to be created.

[roeter]

Track reservation for a train may well extend beyond a signal at danger. Remember there are quite a number of signals which are scripted that these will only clear if the next signal is cleared. If the reservation did not extend beyond this first signal at danger, the next signal could never be cleared and therefor the combination could also never clear.
General rule is : if a signal is requested to clear, and all sections beyond this signal are available, then these sections will be reserved regardless of the signal state.
Also, if within the limits of the required number of signals to clear and if all sections are available, the first signal beyond a signal at danger may be requested to clear.

Regards,
Rob Roeterdink

[Csantucci]

Thanks for explanation, Rob, but again this is a point that provides unnecessary incompatibilities with MSTS way of operating. While your statements justify the fact that sections beyond a signal at danger are reserved, they don't justify the fact that a newly created AI train can't remove these reservations (if after a signal at danger) and can't take these sections for itself.