The nerve center of Atlanta’s electric rail system hides in an unmarked concrete building east of the city limits in DeKalb County, behind a fence topped with three strands of barbed wire. The outer gate opens only with an electronic key card, which also opens the building’s front door. To reach the control room, you pass another tall metal door marked with a sign that says This Door Must Be Locked at All Times. Cell phones are forbidden in the control room. Sunlight is scarce. The bosses of the Metropolitan Atlanta Rapid Transit Authority want no distractions for the workers who on an average weekday keep 242,000 riders safe.
The Rail Service Control Center runs nonstop, seven days a week, with nearly sixty workers in rotating shifts. They are the railroad equivalent of air traffic controllers. Before them, two Mosaic Display Boards dominate the room’s eastern wall. The boards resemble the black grids from the old board game Battleship, magnified a thousand times. They show diagrams of MARTA’s 48.1 miles of tracks, with 750 volts of direct-current electricity flowing through the third rail. The left board shows the trains moving. Each train glows red against the tracks.