Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Object Groupings and Systems (hierarchy name)
4. systems (equipment)
5. [systems by function]
6. infrastructural systems

Narrower term/s

• railroads (infrastructure)
• public transit (infrastructure)[+]
  • [public transit by form] [+]
    • rail transit systems [+]
      • monorails
      • personal rapid transit
      • light rail transit [+]
      • rapid rail transit systems [+]
    • freewheeled transit systems [+]
      • bus transit systems [+]
      • paratransit
    • aerial tramways
  • [public transit by location or context] [+]
    • elevated railroads
    • commuter railroads
    • local transit
    • urban transit systems [+]
      • urban rail systems

Anotations

Scope note:

Transportation systems of attached vehicles, such as trains, that make is possible to move large numbers of people in the same travel corridor with greater efficiency.