underground line
Metro train path
An underground line is a railway or metro route that runs beneath the surface, typically through tunnels in an urban area.
The term is especially associated with London's Underground system: The Piccadilly line was delayed this morning.
It can also refer to buried cables or pipes carrying electricity, water, or gas.
- subwayUnderground transit passage
- metroUrban rail transit
- tunnelEnclosed underground route
- tubeHollow cylindrical passage
- mind the gapHeed the opening
subway car · track · platform · train station · station · commuter · rush hour · rail · secret · covert · resistance · hidden · passage · secret passage · burrow · cable · pipe · conduit
- transit mapsstations, subway map, transit map, train map, transfers
- rail linesA train, D train, L train, Crossrail, scenic railway
- railwaystrains, train, locomotives, locomotive, tracks
vertical position/elevation
underground lineelevated line
Raised urban rail track
elevated railway · elevated train · monorail · streetcar line · light rail
underground, line, under, ground, undergrounds, lines, lined, liner, liners