A new lighting system is being installed on Pittsburgh's sister bridges, and tonight we'll get a glimpse of what they'll look like. Allegheny County Executive Rich Fitzgerald is expected to preview the lights on the Rachel Carson Bridge including three animated light shows. The upriver lane of the bridge will be closed to traffic during tonight's event, which gets underway at 8 p.m. The new lights are also being installed on the Clemente and Warhol bridges.