Interstate 4 at SR 557 Interchange Design-Build

The Florida Department of Transportation (FDOT) District 1 needed to upgrade a vital interchange at Exit 48 on Interstate 4 (I-4) in Polk County, Florida. With more than 100,000 vehicles per day, the existing partial cloverleaf configuration at State Road (SR) 557 no longer sufficiently supported growing traffic volumes, emergency response access, or increasing regional freight movement.  

Simultaneously, the project location bisected the ecologically sensitive Hilochee Wildlife Management Area, where animals were separated by I-4 for more than 50 years. FDOT required a solution that would improve immediate mobility, ensure long-term adaptability to future infrastructure needs — such as express lanes and a high-speed rail (HSR) corridor — and support environmental preservation goals. 

Our team provided construction, engineering, and inspection (CEI) services, delivering a comprehensive transformation of the interchange design configuration, capacity, and connectivity. The existing partial cloverleaf layout was replaced with a streamlined diamond interchange featuring dual teardrop-shaped roundabouts at the ramp terminals. This approach reduced conflict points, improved circulation, and supported large truck movements with reinforced concrete pavement. 

Roadways and bridge structures were designed and constructed at a higher elevation and with expanded width to align with the state’s I-4 Ultimate improvements. The median was widened to 192.5 feet, making space for future express lanes and a high-speed rail corridor. Travel lanes were repositioned outward, mirroring the eventual I-4 configuration, and SR 557 was widened to four lanes for increased capacity and truck movement. The project also prioritized safety and sustainability, incorporating emergency stopping areas on ramps and installing lighting along I-4 and SR 557 to enhance visibility.  

A wildlife crossing under I-4 restored a critical link between habitats on both sides of the highway. Featuring fencing to guide animal movement, the new crossing reconnects the Hilochee Wildlife Management Area and has already welcomed increasingly common wildlife, such as deer, birds, and turtles. The crossing provides new hope for endangered species across the United States — especially native species like the Florida panther — as they migrate north and reestablish critical habitat connections.  

The interchange design-build balanced technical innovation with ecological responsibility, offering a lasting solution that addresses current transportation demands and anticipates future infrastructure needs.