South Carolina Department of Transportation—U.S. 21 over Harbor River Bridge Replacement Project

For over 80 years, the U.S. 21 Harbor River Bridge was the only way thousands of residents, workers and tourists could access a string of three barrier islands on the South Carolina coast. Unfortunately, the low swing-span bridge was deteriorating and sometimes would not close, stranding motorists for hours. As a result, SCDOT created a design-build delivery plan that kept traffic moving throughout construction by using barges to create an access road across the salt marsh and open water. In addition, SCDOT completed a robust assessment to ensure the project included participation in SCDOT’s Disadvantaged Business Enterprises Program. The new $70 million Harbor Island Bridge is a high-level crossing, so vessels can now pass under the bridge without interruption.

The old and new U.S. 21 bridges are seen spanning the Harbor River in Beaufort County, SC, on Oct. 7, 2020.