Hi there! On a personal note (I’m a United States person) I have experience where footbridges are often (NOT ALWAYS) used as a focal point on a trail where you might actually meet up with people, stop while biking for a quick drink, or where kids will play under. Since bridges are usually over something, the clearing makes them a place people would actively engage with to take photos of over a clearing (if a wooded area) or might jump off of into a stream or river.
On another note, there was an old deleted Ingress AMA that explicitly stated “…wooden footbridges on a trail are eligible” and that was a very unhelpful statement as it lead to some people nominating every parking lot culvert and others rejecting every bridge adjacent structure not explicitly wooden and not explicitly on a named trail. Later, an AMA was published for Wayfarer specifically (which has since been deleted) that read:
What types of bridges are and aren’t eligible?
In general, think about the specific bridge and whether it’s a clear and differentiable location for other players to find. Also, if a location is somehow important to the community, it would also be a good candidate. Our guidance for most locations is whether a location, structure, piece of art, etc. is important for exploration, promotes exercise or facilitates social connections. With regard to bridges generally, if it is accessible by foot and expected to be used as part of a named path or trail, it would meet criteria. Bridges that primarily serve cars and don’t have pedestrian access are not eligible.
I must reiterate that it has been deleted. However, I think the value fits nicely and is all we really need for much of any criteria.