Historic Fourth Avenue Underpass

Historic Fourth Avenue Underpass. Constructed 1916 – Demolished in 2008. , Tucson City Engineer ― J. Mos Ruthrauff , Design Engineer ― L. R. Walker , Contractor ― Bent Brothers, In 1913, in an effort to separate pedestrians, vehicles, bicycles and wagons from trains, the City of Tucson embarked on a major grade separation project to have Fourth Avenue, a major thoroughfare in Downtown Tucson, travel beneath the Southern Pacific Railroad., The original underpass consisted of two 12-foot-wide lanes and 6-foot-wide raised pedestrian walkways on each side. The underpass was approximately 257 feet long so that it could carry up to eleven railroad tracks. The structural system was cast-in-place reinforced concrete skewed slab spans supported on concrete walls and columns. The underpass featured a classical revival architectural treatment with recessed rectangular panels cast into the walls. A series of 3-foot-high concrete posts, connected with heavy chains served as railings to separate the sidewalks from travel lanes., Before being demolished in 2007, the original underpass was recognized as Arizona's oldest urban grade separated roadway and it was listed on the National Register of Historic Structures.