From SH Interlocking (MP 0.0), where the Merchants District from Bremen and May Street, over the Merchants Bridge, arrives from the west, and splits into three tracks, once turning north, still on the Merchants District, to WR Tower, one turning south, on the Wiggins East Side District along the west side of the TRRA Madison Yard, and one heading just south of due east, on the Illinois Transfer District, single track, Traffic Control System, maximum speed 20 mph, past a flat crossing with the connector between the Wiggins East Side District and the line to WR Tower, a location where there was once a bridge carrying the erstwhile Illinois Terminal line overhead, the junction at GC Cutoff (MP 0.3), where a line turns east to East Madison Junction and the former C&NW Madison Yard, and the Illinois Transfer District turns south, with a connector from the WR Tower line trailing in on the east side, becoming Double Track, Automatic Block Signals, past the crossover at Cut-Off Crossover (MP 0.4), along the east side of the TRRA Madison Yard, and (near the south end of the yard) a location where a bridge once carried another erstwhile Illinois Terminal line overhead, and turning south-southeast to the flat crossing with the NS (former Alton & Eastern), and the junction with a TRRA line from the East Wiggins District at CP Connection, trailing in on the west side at CP Junction (MP 1.3), where there was once also a flat crossing with the former Nickel Plate.