Trivia or Lifesaving Information?

I just found out that the Tremont / Boylston intersection walk lights are not always “all walk” (I think of Kat and her board games and I think “All Play”) as I had assumed! ┬áSo this means that you can not necessarily safely cross on the┬ádiagonal, as I would want to do, just because one corner has the white-walky-guy of “go!”