Train facing direction filter on waypoints
Add a filter to waypoints that allows or denies trains depending on their facing direction. This would allow control over train facing directions, e.g. by forcing trains onto wye's to turn around if not traveling forward, or send trains into stations with (un)loaders matching the train layout.
I'd suggest the following filter options,
Forward
Forward or Symmetrical
Symmetrical
Reverse
Reverse or Symmetrical
To account nicely for symmetrical trains