Traverse all passages

I have stuff like: <<timed 21s>> in my passages. Each one has it. Is there a way to traverse all the passages in a recursive manner and calculate the most amount of time that a user can go from passage X to passage Y ? I know there are possible issues of infinite loops, but I'll handle that. I first need to figure out if I can traverse all the passages, how to get a reference from one passage to any other that it points to and then retrieve the `timed` value.

Any ideas?