In 2005, a control room for the A and C subway lines in NYC caught fire. "No larger than a kitchen," the room held 600 relays, switches and circuits that keep track of trains and keep everything running. Officials originally thought it would take three to five years to get the lines back to normal capacity. (Thankfully it didn't.) The epic repair time was because the fixed-block signaling system dates back to 1904 and only two companies in the world were able to repair it, one in Pittsburgh and the other in Paris. This is technology's trailing edge, according to Peter Sandborn in IEEE Spectrum: the huge, crippling problem of obsolescence.