Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Built Environment (hierarchy name)
4. Single Built Works (hierarchy name)
5. single built works (built environment)
6. [single built works by specific type]
7. [single built works by function]
8. transportation structures
9. [transportation structures by form]
10. bridges (built works)
11. [bridges by construction]

Anotations

Scope note:

Bridges, generally temporary, with decks supported on low flat-bottomed or hollow floats, often used by the military for river crossings. Permanent pontoon bridges may be used for crossings where it is not feasible to suspend a bridge from anchored piers.