Closing a Gap in a Historic Trail Network in the Florida Keys

The Florida Keys Overseas Heritage Trail consists of approximately 100 miles of multiuse trail from Key Largo to Key West, Florida. Maintained by the Florida Department of Environmental Protection (FDEP), the trail system was developed by incorporating the bridge and right-of-way network from the defunct Overseas Railroad. Two of the primary historic bridges, the Seven Mile Bridge and the Bahia-Honda Bridge are severely deteriorated and closed, creating a missing link in the 100-mile trail system. Gresham Smith was called on to inspect and evaluate the bridges and develop recommendations for either rehabilitating or replacing the bridges.

Because of the advanced deterioration of the bridges, the inspection team had to carry out much of the conceptual inspection via drones. The Seven Mile Bridge evaluation includes the southern 4.5-mile segment south of Pigeon Key Island, including both steel plate girder and concrete arch spans. The Bahia-Honda Bridge is a 32-span steel truss that was previously converted from a thru-truss railroad bridge to a deck-truss vehicular/trail structure. Rehabilitation and replacement options with cost estimates were developed for the Seven Mile Bridge. Based on the severe condition of the Bahia-Honda Bridge, demolition and replacement options were evaluated since rehabilitation is not prudent. The recommendations also included “immediate action” recommendations for a buoy/signage program to preclude boater access under the Bahia-Honda Bridge. FDEP is currently reviewing our recommendations.