CHARLESTON COUNTY, S.C. (WCBD) – The estimated cost to extend I-526 has surpassed two billion dollars.

The South Carolina Department of Transportation (SCDOT) project team has been working on traffic and environmental studies as part of a plan to extend the Mark Clark from West Ashley to James Island.

In a letter to the county this week, Secretary of Transportation Christy Hall told leaders that updated estimates for the project now factor in the current real estate and construction markets and the expected cost of inflation over the next several years.

That number now totals an estimated $2,352,000,000.

“The estimated cost for the project has increased significantly, however, it still remains just an estimated cost,” said Hall.

Hall said the majority of the increased project costs come from increased land prices, higher material costs, inflation, and anticipated legal challenges to the proposed project.

The extension project is separate from other upgrades and construction already being considered along I-526 from West Ashley to Mount Pleasant. Hall said it is important to ensure funds will be properly allocated.

“We will need some level of assurance from the county… and the Infrastructure Bank that there is a reasonable availability of funding to build the whole project,” Hall said.

Charleston City Council approved an Emergency Resolution during its council meeting Tuesday night urging the partners to move forward with the project, completing the Mark Clark Extension to improve life and conditions for city residents.

“No question, the cost estimates for major infrastructure projects in South Carolina are exploding, and 526 is no exception. But that doesn’t change the fact that our West Ashley and island residents need and deserve the traffic relief and public safety improvements this project will bring. That’s why, tonight, I’ll be asking City Council to support an emergency resolution endorsing County Council’s efforts to move forward with this critical project,” said Charleston Mayor John Tecklenburg.

The expansion project is in the planning and preparation phase. Secretary Hall is hopeful the project will be able to go out for bid after the preparation work has been completed. When the project begins, it is expected to happen over the course of two phases.

This is a developing story. Count on 2 for updates.