When the U.S. Army 7th Special Forces Group relocated to Eglin Air Force Base, traffic at the intersection of SR 85 and West McWhorter Avenue was projected to surge from 200 vehicles per day to more than 7,000. To support this dramatic increase, the Eastern Federal Lands Highway Division advanced a major design‑build initiative to construct a new grade‑separated interchange. As part of the Lane Construction Corporation team, STV provided overall design management and engineering support to deliver an efficient, safe and cost‑effective interchange solution.
What challenges did STV address?
The existing diamond interchange could not meet projected traffic volumes and was constrained by nearby wetlands and crossroad alignment issues. The team needed an interchange configuration that improved operations, minimized environmental impacts and could be delivered on an accelerated design‑build schedule. Avoiding impacts to sensitive areas while improving mobility and safety required an innovative rethinking of the interchange layout.
What solutions did STV deliver?
STV evaluated multiple concepts and advanced a half-cloverleaf design featuring two loops, linear ramps, signalized intersections and a new 247-foot bridge. The layout realigned the crossroad and avoided wetland impacts while improving traffic flow. The team developed an evolving 3‑D computer model early in the design process to support grade control, survey layout and design accuracy. The approach saved the client $3 million and allowed the interchange to open four months ahead of schedule.
How does this project benefit the community?
The new interchange accommodates significant military and civilian traffic growth, reduces congestion and delivers safer movements for all users. By avoiding wetland impacts and improving regional mobility, the project supports both environmental stewardship and mission‑critical operations at Eglin Air Force Base.
Key stats and accolades
- Half‑cloverleaf interchange configuration
- 247‑foot bridge
- Saved $3 million in project costs
- Opened four months ahead of schedule
- Avoided impacts to adjacent wetlands
