After further observation I can provide an answer to the question that was raised about the "LOOK" signs on the light rail. The lights in them that flash are red, not yellow. What flashes is not plain lights, though, it is the text "SECOND TRAIN".
This text, naturally, only flashes when two trains are approaching the crossing from opposite directions. When there is only one train the LOOK signs do not flash. There is, however, always some other method of warning when a train is approaching.