I few days ago I suddenly realized that my son's small digital camera had some crude video capabilities (which mine more expensive one does not). And today I managed to shoot a short video showing one of my ABS signals at work.
An approaching train (well an engine running light) is in the block beyond the signal, so it shows red. When the train has passed the signal it automatically changes back to green. The train comes at quite a high speed, but that is because the camera would not allow longer videos than 10 seconds, so I did not have that much time.
I'll see if I can manage the sequence in the opposite direction; green - red - yellow - green. But then I probably need to split it on several short clips. Unless I learn how to edit videos so I can append them into one longer.