So, it’s triggered by anything moving toward it - even a pedestrian. I think the white square is a radar sensor, that detects motion toward (not away) from it. It only activated if you move toward it.
My guess? Since this is right at the end of the Willis Way platform, it’s a quick and easy way to get the NO TURN/TRAIN sign to come on when the train is actually moving toward it... not just when it’s sitting there, since it might be stationary, loading.
My guess? Since this is right at the end of the Willis Way platform, it’s a quick and easy way to get the NO TURN/TRAIN sign to come on when the train is actually moving toward it... not just when it’s sitting there, since it might be stationary, loading.