The modification of the existing I-485/I-85 interchange into a fully directional turbine interchange was the final link in the 67-mile-long circumferential loop around Charlotte, NC. A first-of-a-kind roadway structure in the state, the North Carolina Department of Transportation (NCDOT) anticipates 180,000 motorists will use the corridor daily by 2035.
NCDOT initiated a design-build-finance advertisement for teams to submit qualifications for the $124-million project. The Lane Construction Corporation/STV design-build team proposed the replacement of the four-level stack with a two-level turbine interchange.
By switching to the turbine layout, the Lane/STV team helped NCDOT achieve numerous advantages which enhanced safety for both motorists and construction workers, while also providing significant cost savings. The project included widening 2.5 miles of I-85 to accommodate additional ramp lanes, widening/construction of 1.5 miles of I-485, and the turbine interchange, comprising eight ramps/loops and 19 bridges.
The project saved NCDOT $50 million and earned a National Award of Excellence from the Design-Build Institute of America, among other awards at the state and national level, recognizing it as one of the top design-build projects in the country.
$50m
project budget savings
67 miles
circumferential loop length
180,000
daily motorists projected by 2035
