Junctions.
CTA Green Line trains shuffle to and from Roosevelt Station, with 5000-series no. 5127 (Bombardier, 2009-2015) leading the loop-bound train. Just south of here, the connection to the Red Line joins as the two express tracks, then the Orange Line branches off to go to Midway.
A continuously growing album of photos that IMHO reveal the awesome and seldom-seen beauty of the railroad world from the dimming of day to dawn's early light! From dusk to dawn, trains roll on! (I'm still finding gems of sunset-to-sunrise surprises!)