The Circumferential Line north of the Fresh Pond Yard would
use the New York Connecting Railroad line, which proceeds through
Middle Village in a trench.
The BMT Myrtle Avenue Line (M train) terminates at the Metropolitan Avenue Station.
The NYC Connecting Railroad freight track runs just a few feet east of the BMT tracks, so
building platforms and a transfer path should not be difficult.
The NYC Connecting Railroad then proceeds through a short tunnel under Metropolitan Avenue
and a portion of Lutheran Cemetery before emerging in a trench.