There are two adjacent stub-end terminals at Randolph Street (MP 0.0), with the newly-built (in 2006) Millennium Station passenger facilities, below ground, replacing those at the ground level of the (former) Prudential building: the Metra Electric (former IC Suburban) station to the west, having three platforms serving six tracks, and the Chicago, South Shore and South Bend ("South Shore" or Northern Indiana Commuter Transportation District) station to the east, with two platforms serving four tracks. The north-south oriented platforms and tracks were all in the open air in 1993, but in 2006 are all underground or beneath structures at higher levels. All tracks, electrified with overhead catenary, run through a common station throat onto a common pair of tracks heading due south, on the east side of Michigan Avenue, emerging into the open, depressed in a trench with retaining walls, and then almost immediately passing beneath the rearward extension of the Art Institute of Chicago onto the parkland to the east, and then passing a road bridge overhead, the station at Van Buren Street (MP 0.8, west side plus island platforms below street level with station buildings at street level and the eponymous road bridge overhead within the station), just north of the former Congress Street station location, two road bridges overhead, extra track on the east side and storage tracks in the center, and the station at Roosevelt Road (MP 1.43, two island platforms, with extra center track between them, and a far east side platform, all connected with a pedestrian bridge overhead where the depot facilities are located, adjacent to the north end of the erstwhile Central Station trackage to the west of the line).
The four electrified tracks pass a road bridge overhead and more storage tracks in the center. The Metra 18th Street Yard (carriage sidings) lies alongside the west side of the line, to the south of the former location of Central Station, ending just north of the station (wooden center island between the two inner track only, pedestrian bridge overhead) at 18th Street (MP 2.22), where the former Illinois Central main line tracks began on the west side. The Metra Electric tracks jog southwest to pass beneath the bridge carrying the IC main line (which, since the closure of Central Station, comes east from the St. Charles Air Line and 21st Street Junction), located at the north end of the McCormick Place exhibition and convention facilities, and then turn just east of due south, with the IC main line descending alongside to the east, beneath the McCormick Place structures, past the station at 23rd Street-McCormick Place (MP 2.68), a center island platform also beneath the overhead structures, a hospital on the west side, triple road bridge overhead just south of McCormick Place, the wooden center island platform of the station at 27th Street (MP 3.20), in a track formation now comprising two electrified tracks to the west and the two IC main track on the east side, Intermediate Signals, and the closed station at 31st Street, of which no sign remains in 2006.
There is a road bridge overhead, a pedestrian bridge overhead, and a road bridge overhead, with the line angling south-southeast, past the closed station at 43rd Street, of which no sign remains in 2006, Intermediate Signals, Intermediate Signals on the IC main, Intermediate Signals, a pedestrian bridge overhead, Intermediate Signals, and the station (west side and island platforms) at 47th Street (MP 5.90), where there are now three electrified tracks on the elevated formation passing above many city streets, and turning south-southwest past a bridge over an east-west street, crossovers at 51st Street, where four electrified tracks begin, a bridge over 51st Street, a bridge over 53rd Street, the station (two wooden island platforms, facilities below) at 53rd Street (Hyde Park) (MP 6.54), Intermediate Signals on the IC main, a bridge over 55th Street, the station (two wooden island platforms, facilities below) at 56th Street (MP 6.99), a bridge over 56th Street within the station, a bridge over 57th Street, south of the station, Intermediate Signals, the station (two wooden island platforms, facilities below) at 59th Street (University of Chicago) (MP 7.43), a bridge over 59th Street at the south end of the station, Intermediate Signals, the station (two wooden island platforms, facilities below) at 63rd Street (MP 7.92), where CTA elevated trackage to Jackson Park once bridged overhead, signals and crossovers, signals and crossovers on the IC main, a bridge over an east-west street, and the station (two wooden island platforms, facilities below) at 67th Street (MP 8.33).
Just south of the latter, and a bridge over 67th Street, are crossovers and a junction where the Kensington line (the outer two tracks) continues ahead while the South Chicago branch (the inner two tracks) descends, passes beneath the formation, and curves away to the east.