Big Carlos Pass PD&E Study and Final Design

KCA was selected to lead the PD&E study and design for the Big Carlos Pass Bridge replacement. The existing bridge over the Big Carlos Pass provides connection between Fort Myers Beach and Lovers Key State Park and is a single leaf bascule bridge with a horizontal clearance of 50 feet and a vertical clearance (when closed) of 24 feet 6 inches at the main channel and a total bridge length of 1,688 feet. This project involved overlapping the PD&E Study with the final design so the overall timeframe for the complete project delivery was shortened significantly. While the overlapping of PD&E and design shortened the project schedule, the sudden development of COVID-19 lengthened the total schedule. This also required the entire team to make adjustments as the traditional way of doing business was rapidly evolving.

The PD&E study considered both rehabilitation and replacement options as well as movable and high-level fixed bridge alternatives. The study was conducted in accordance with National Environmental Policy Act (NEPA) requirements to develop the purpose and need for the project and to determine the environmental class of action following the FDOT PD&E Manual and using the Efficient Transportation Decision Making (ETDM) process. Ultimately, a bridge replacement with a high-level fixed bridge was the selected alternative to move forward to final design.

The superstructure includes a concrete deck with eight Florida I-Beams supported on end bents and hammer head piers. Optimized footings with 24-inch prestressed concrete piles are utilized for vessel collision. Big Carlos Pass is an extremely active coastal environment that required detailed scour and wave analysis, which was included in the final design of the piers. The navigation channel was shifted approximately 300 feet to allow the new profile to tie back to grade with only minimal impact to the adjacent condominium entrances.

Multi-modal attributes to accommodate pedestrians, bicyclists, and the local LeeTran trolley system were incorporated into the project. The KCA team conducted the environmental and structural analyses, led public involvement/information meetings, obtained and analyzed traffic data, developed conceptual design plans, coordinated with utility agency owners (UAOs), eliminated potential right-of-way (R/W) impacts, and developed cost estimates.