Here are three examples of One Way bridges within a few miles of my place.
The Big Bridge over muddy flood water (taken in the rain, sorry about the spots.)
The Middle Sized bridge
and the Little Bridge just before my house
This one is a little further away. Must be used by more traffic because it warrants a one way sign.
I took this one last Sunday in Matakana. Yes, it was raining then, too but the trees were giving me some protection.
Also at Matakana, a little footbridge:
I will check the bridges from the rest of the FSO team when I get back.