When a train passes a train signal on both side to indicate one direction of a defined speed, but the opposite direction is unrestricted it triggers the train to slow as the directional train passes but as the opposite facing passing the signal of unrestricted it triggers unrestricted for the entire train.

So the problem is that the speed limit also affects trains going in the oposite direction of the signal?

So if you run double headed trains, the one facing in the opposite direction of travel will get the speed applied to the entire train not just the train facing the direction of travel so you end up traveling slower or faster depending on your setting that what you wanted.

Right side precedent is in play.

 $unl                                  <-$80kph

 -Unl->              <=1=| - |=2=>              -???->

 $unl                                  $40kph->

Love the mod btw, so many less deaths in the train yards pre-mech armor :-D