The Red Line Subway at Union Station is located relatively deep beneath the station above. The stop has a single island platform and the tracks continue beyond the station to reach the Red Line's mostly outdoor train yard, visible from the 1st Street Bridge (visible from the Gold Line) and the 4th Street Bridge. The station opened on January 30, 1993 on the initial operating segment. Operationally trains normally come in on one of two station tracks and relay within the station. The doors though are open and closed twice. Once to discharge passengers (and leave service), then to let security, always stationed at the station kick everyone (including the homeless people) off the train who I've witnessed using the emergency door opening handles. The train operator change ends, opens the doors and soon leaves. The station lacks an indicator for which track leaves next but this unusual routine of kicking everyone off the train makes them not necessary.
The station has simple concrete walls and exits at either end to the buildings on each side of the Gold Line, Amtrak and MetroLink platforms. At either end of the station's island platform are two up escalators/staircases and an elevator that lead up to fare gates followed by another set of escalators/stairs and an elevator up to the actual exit into the respected building. The west end leads into Union Station with the red line's entrance right inside the main lobby. The mural L.A. City of Angeles by Cynthia Carlson is above the first set of stairs/escalators into the station. The opposite eastern exit leads to the Gateway Transit Center via a similar arrangement passing Traveler by Terry Schoonhoven. The two exits from the station are connected towards street level by the wide underpass that provides the only access to all of Union Station's 5 platforms plus the one platform to the Gold Line alongside those that is closest to the Union Station end.
June 19, 2013 Turnstile Latching: The station became the first L.A. Metro Station to finally have its turnstiles latched (the rest of the Red and Purple Lines will be phased in through the Summer of 2013) as part of a long project that began with the turnstiles first installed in Union Station in 2009. One of the major hold ups was MetroLink that finally in 2013 unveiled a TAP Compatible ticket with a microchip inside it. At both entrances there are two banks of turnstiles with pillars in between them. All turnstiles are bidirectional (you don't have to TAP out to exit, exiting always works by pushing through) but Metro has put up Green and Black stickers on the floor to try and designate one bank of turnstiles at each of the two entrances for exiting passengers and another for exiting ones. Staff when present is also directing passengers to use the correct side (in New York we don't need to be separated!) and at the Gateway Transit Center exit a small chain corral has even been put up close to the entrance gates to emphasize exiting at the other bank of turnstiles. The practice of kicking everyone off arriving trains also seems to have ended, they now simple relay in the station with passengers on board.
Photos 1-7: April 14, 2006, 8-22: March 18, 2010, 23-26: February 25, 2012, 27-28: March 4, 2011, 29-33: June 20, 2013, 34-40: June 23, 2013; 41-43: