Any chance there is a (small) tutorial on how the A.S.S. works (with your signals)? It seems i get mixed results.
Some signals do not show any lights at all but train seem to think speed is set to 40.
Other signals show 80 on yellow, despite a different speed set in the option.
Some signals immediately turn red upon the train reaching the signal, others turn red after the train has passed the signal.
When stopped before a red signal that then goed to a yellow signal with restricted speed, the train ignore this speed limit.
Trains also only increase their speed once they are fully out of the slower block. Not upon reaching the higer speed signal.