Design of the Cross Florida Greenway Land Bridge Over I-75 Using Precast Florida U-Beams

The Cross Florida Greenway is a multiuse trail that bisects the central region of Florida, an area that was originally set aside for the Cross Florida Barge Canal. After Congress deauthorized the barge canal, the Cross Florida Greenway State Recreational Area was created, and the canal property was turned over to the state. Interstate 75 interrupts the Cross Florida Greenway in Marion County in a north-to-south direction for a distance of about 1829 m (6,000 ft) along the I-75 centerline. No bridges or underpass structures currently exist that connect both sides of the Greenway. Through several years of study, the Florida Department of Transportation and the Florida Department of Environmental Protection developed a land bridge concept for traversing the I-75 right-of-way while continuing the Greenway characteristics across the bridge. The land bridge concept is used internationally and is conducive to wildlife usage. The structure will be 16 m (52.5 ft) wide. It will provide a stabilized section along the center portion of the bridge for bicyclists, pedestrians, and equestrians, as well as earthen berms to support plantings along the outside edges of the structure. The key unique structural elements of the bridge, which is the first precast U-beam superstructure to be constructed in the state, include use of open triangular-shaped median piers, integral abutments, and geosynthetic-reinforced, vegetated approach slopes. The project is expected to attract national and international attention because it may be the first of its kind in the United States and because of its location along the heavily traveled I-75.