Tucson City Engineer ― Jim Clock
Design Engineer ― Cannon & Associates, Inc. TranSystems Corp.
Contractor ― Sundt Construction, Inc.
Long known as the Gateway to the East End of Downtown, the Fourth Avenue Underpass in a vital link between the University of Arizona, the Fourth Avenue merchants and the Downtown Tucson Business District. In 1988, as part of a movement to revitalize the Downtown area, the City of Tucson moved to reconstruct the historic underpass to improve access under the Union Pacific Railroad and to provide the framework for Downtown Links, the final mile of the Barraza-Aviation Parkway.
With two 14-foot-wide travel lanes, raised sidewalks (8-foot-wide on one side and 20-foot-wide on the other), dedicated 6-foot-wide bicycle lanes, provisions for the Tucson Modern Streetcar, and two overhead pedestrian bridges, the new Fourth Avenue Underpass greatly improves all modes of travel between the City Center and bustling Fourth Avenue businesses.
The Fourth Avenue Underpass is 245 feet long and supports three railroad tracks and Downtown Links. The structural system consists of cast-in-place reinforced concrete skewed slab spans supported on concrete walls and columns. The underpass features a modern architectural treatment with rusticated retaining walls, oval-shaped concrete columns, and metal railing to separate vehicular travel lanes and pedestrian walkways. The reconstruction of Fourth Avenue Underpass began on June 21, 2007, and opened to traffic on August 20, 2009. The reopening dedication was attended by nearly 10,000 people who celebrated this transportation milestone for the Tucson Community.