We applied our expertise in evaluating steel structure fatigue life and seismic deficiencies to develop 3D modeling for preliminary design services for this $150 million design-build rehabilitation of a 100-year-old, 199-span rail transit viaduct in Brooklyn, New York. We specified intricate construction phasing to keep one track in service at all times (with two at rush hour) and developed an hour-by-hour schedule to accomplish work on weekends, as mandated by the client.