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]

Narrower term/s

• bridge elements [NP][+]
  • bridge approaches
  • cutwaters
  • bridge towers [+]
    • lift bridge towers
    • structural bridge towers
    • fortified bridge towers
• [bridges by form][+]
  • arch bridges [+]
    • tied-arch bridges
    • open-spandrel arch bridges
  • movable bridges [+]
    • drawbridges
    • bascule bridges
    • lift bridges
    • swing bridges
    • transporter bridges
  • skew bridges
  • trestle bridges
  • covered bridges
  • multispan bridges
  • single-span bridges
  • boardwalks [NP]
  • inhabited bridges
  • pavilion bridges
  • yatsuhashi (bridges)
  • truss bridges [+]
    • continuous bridges
    • deck truss bridges
  • truss arch bridges
  • clapper bridges
  • step stone bridges
  • log bridges
• [bridges by function][+]
  • footbridges [+]
    • skybridges
  • military bridges
  • viaducts [+]
    • road bridges [+]
      • toll bridges
    • railroad bridges
• [bridges by construction][+]
  • bailey bridges
  • cable-stayed bridges
  • cantilever bridges [+]
    • balanced cantilever bridges
  • pontoon bridges
  • girder bridges [+]
    • bow-string girder bridges
  • pile bridges
  • suspension bridges
  • stress ribbon bridges [+]
    • footbridges [NP] [+]
      • skybridges
  • beam bridges

Anotations

Scope note:

Structures spanning and providing passage over waterways, topographic depressions, transportation routes, or similar circulation barriers.