Lets see here
Detroit Mi.
NS (Dearborn sub), + Ex Conrail, (Michigan Line, Detroit Line Jct Yard Secoundary)
CSX (Saganaw sub) + Ex Conrail ( North Yard Branch, Sterling secoundary, Lincoln Secoundary Belt line (aka rust belt secoundary)) And i think whats left of the DelRay Connecting railway
CN (River Sub) + GTW (Flatrock, Holly sub, Port Huron sub, and river sub) DT&I (Shore Line Sub)
CP (Tunnel Yard Sub) .. i think, don't quote me on that one.
DT (Detroit Terminal RR) A little Indy switching rail road, mostly limited to Zug Island area
TSBY ( They owen whats left of the MI Centeral and a lot of other little short lines)+ Some of the old C&O and B&O
You would think there would be a lot of traffic, but when the auto indy started to tank, a lot of the traffic went with it.
Please forgive the spelling errors, it's 1:30 in the morning!