Part of the 110-mile (177-kilometre) Florida Keys National Scenic Byway and All-American Road, Long Key Bridge is the second longest bridge on the Overseas Highway, after the Seven-Mile Bridge. Constructed in 1981 parallel to the historic Long Key Viaduct—which carried the Overseas Railroad from 1907–1935—the bridge is a vital hurricane evacuation route and a critical connection for residents, visitors, freight, emergency services, and utilities serving the Lower Keys.
The bridge has been repaired six times in the intervening years to extend its service life. The Florida Department of Transportation (FDOT) decided it was time to consider replacing the structure entirely, and they reached out to us to conduct a project development and environment (PD&E) study.
As part of this study, our team performed environmental and engineering analyses evaluating rehabilitation and replacement options for the bridge. Maintaining bridge operations is key, as the crossing also supports essential services such as water and fiber-optic utilities. We developed alternatives as they relate to roadway and bridge design criteria with the goal of minimizing impacts to the community and the natural and physical environments. Our field teams documented natural resources around the bridge and surrounding waters, including marine habitat and organisms on the existing structure.
We continue to coordinate with federal, state, and local agencies and public invested parties to inform the development of project alternatives.
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