Yes, it's called common sense. Kind of like crossing a crevice on a glacier, you don't do it unless you are roped off. Come on Bee
Well, um, thanks for the advice -- I feel so much better, now.
Perhaps I was a bit vague; my query was in regard to any visual cues that a bridge may be weakening. I am not that experienced, thus, trial & error is very unappealing at this point.
I will keep your advice close at hand should I decide to wander over any glaciers/
crevasses.