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 form]
12. arch bridges

Anotations

Scope note:

Arch bridges in which the outwardly directed horizontal forces are borne as tension by means of a cord tied to the arch ends, rather than by the ground or the bridge foundations. Because of the typically curved shape of the arches, it was also known as a bowstring arch.