At Q Tower (MP 281.0), the TRRA Yard Limits single track line coming northeast from M&O Junction (and the TRRA CTC single track line coming north from Trendley Avenue) join with the Two Main Tracks, Traffic Control System, line northeast from the TRRA MacArthur Bridge District, where a number of lines coming east from the river bank (including the erstwhile TRRA line from the Eads Bridge—now used by MetroLink light rail trains—once used by PRR passenger trains) used to trail in or cross at grade, and today's line splits into a TRRA line heading north-northwest to Bridge Junction, a TRRA line heading north-northeast (the Eads Conologue District), a Gateway Eastern (formerly PRR) line heading northeast and a CSX (formerly B&O) line heading northeast, all past the former location of Relay station just north of Q Tower.
The former PRR line, single track, Yard Limits, maximum speed 10 mph, heads past the south side of the erstwhile Relay station, and then past the flat crossing and north quadrant connector with the former B&O at K Tower, aka K Connection (MP 238.6), curving east-northeast, with the former B&O not far to the south, past Willows (MP 237.0), where there are flat crossings with the NS (former Venice & Carondelet Belt) and TRRA lines, and was once an intersection with an erstwhile Illinois Terminal interurban line, as well as an end on junction with the former Conrail St. Louis Line, which now becomes Two Main Tracks (Track 1 Automatic Block Signals, eastbound; Track 2 CTC), maximum speed 20 mph.
The line passes Rose Lake Yard (MP 235.4), on the north side, the junction (northwest quadrant) and flat crossing with the Alton & Southern line from Granite City to Gateway Yard, at HN Cabin (MP 234.0), where single track, CTC, starts and the maximum speed rises to 70 mph for intermodal trains, 50 mph for other freight trains, and 40 mph for general merchandise trains, a detector at "Exermont" (MP 233.8), where the erstwhile Exermont Yard once was on the north side of the line, the 7,500 ft. controlled siding and resumption of 2MT at CP Exermont (MP 232.5), Griswold, where the line turns just south of due east and the former B&O moves away on the south side, and Caseyville, wehre the line turns east-northeast.
There are detectors at "Collinsville" (MP 228.3), a 60 mph speed restriction on curves, from MP 227.5 to MP 225.5 as the line turns northeast, past Collinsville (MP 227.5), and just south of due east, past Cantine, where a branch once left on the north side, turning just north of due east, past a (former?) bridge carrying an erstwhile L&N line overhead, and Pait, northeast to the start of single track at CP 220 (MP 220.5), where that erstwhile PRR branch once trailed in from the west and the line turns just north of due east, past east a detector at "St. Jacobs" (MP 216.0), St. Jacob, the 6,750 ft. siding at Highland (MP 209.0), CP 208/"Highland" (MP 208.6), where a 22,900 ft. controlled siding starts, a 65 mph speed restriction, from MP 207.1 to MP 205.5 as the line turns northeast, CP 204/Pierron (MP 204.2), where the siding ends, a detector at "Pocahontas" (MP 201.4), and Pocahontas.
The line turns east-northeast, past Stubblefield, northeast and then just south of due east, past CP 160/Greenville (MP 189.5), east-northeast, past Smithboro (MP 187.0) and the 16,360 ft. controlled siding at CP 186/"Smithboro" (MP 186.4), where there is a flat crossing (50/40 on the crossing) with the BN southern Illinois coal line, east past a detector at "Mulberry Grove" (MP 182.0), Mulberry Grove, and Lutz Spur, east-northeast past Hagerstown, the start of a 15,000 ft. controlled siding at CP 174/W. Vandalia (MP 175.7), east past Vandalia (MP 173.0), where there was once a flat crossing with the erstwhile Illinois Central "main line" from Centralia to Freeport, and is still a stub of that line on the north side, a 60 mph speed restriction between MP 172.8 and MP 172.2, the end of the siding at CP 172/E. Vandalia (MP 172.6), and a turn east-northeast.
There is a detector at "Brownstown" (MP 164.0), Brownstown, Avena, a detector at MP 157.9, the junction with the UP (former C&EI) southern Illinois line at CP 157/W. St. Elmo (MP 157.8), start of 12,500 ft. controlled sidings on both north and south sides of the line, and the ends of both sidings and the junction with the UP (former C&EI) line to Chicago at CP 154/E. St. Elmo (MP 154.3).