Chicago’s Lakefront Trail Pedestrian Bridge incorporates architectural steel railings and panels, custom steel deck nosing and a LED lighting system to improve visibility, but the real star of this Lake Shore Drive attraction is the steel spine fabricated from a pipe that ranges from 1 in. to 1 7/8 in. thick with a 30 in. diameter.  T-shaped webs and flanges are welded to the top of the pipe for additional strength, providing a surface for sheer studs that allow for composite action between the steel and the path’s concrete deck. The bridge used concepts typically found in roller coasters, a first-time application on a North American bridge. Challenges included a Superfund site by the Chicago River and unknown conditions in the existing Lake Shore Drive bridge house.