The bridge replacement is a county project that's moved forward with considerable input and permissions from the Town of Hilton Head Island. Ultimately, it's the DOT that owns and maintains the span of bridges connecting Hilton Head to the mainland, and it's that department that will have the final say.

DOT built the Mackay Bridge in 1956 and widened it in 1984.

The state agency inspects all bridges in South Carolina at least every two years. Due to the age and condition of the MacKay Bridge, DOT inspects it annually.

An inspection in January 2024 rated the structure and substructure as “poor.” While the bridge is safe to drive over, it is approaching the end of its life and has been placed on a statewide priority list.

The U.S. 278 corridor project has taken many conceptual forms over the years. Through the project, the county and DOT aim to make improvements to the corridor between Bluffton and Hilton Head Island, from Moss Creek Drive to Spanish Wells Road.

As the town and county spent years debating the best route forward, the pandemic began, inflation increased, construction slowed and the estimated cost of the bridge rose by 60 percent.

The county did have a plan to cover the costs. A $950 million sales tax referendum would have implemented a 1 percent sales tax for 10 years, with the goal of spending the money to improve the county's transportation infrastructure. About $90 million was earmarked for the bridge project.