ATLANTA — The Georgia 400 Express Lanes project, already the most expensive infrastructure effort in state history, has secured a major funding boost. The U.S. Department of Transportation has approved a federal loan of up to $3.89 billion to help fund construction of 16 miles of new express lanes along Georgia 400.

The project will add new lanes in both directions from the MARTA North Springs station to just north of McFarland Parkway. Officials say the express lanes are expected to shave about 15 minutes off the average commute for drivers.

The express lanes initiative is part of a public-private partnership, which state leaders say allows the project to move forward without placing additional financial burden on taxpayers. Georgia DOT Commissioner Russell McMurry explained the funding strategy when the project was first introduced, “The construction gets funded through private investment, which ultimately gets repaid through the users of the express lanes.”

Governor Brian Kemp welcomed the federal funding, calling the project a long-term investment in Georgia’s economic competitiveness. “This financing will boost the state’s competitive edge and make it easier for hard-working Georgians to commute,” he said.

Preparation work is already underway, with construction expected to take approximately six years. According to the Governor’s Office, the Georgia 400 Express Lanes project is also the largest public-private partnership in U.S. Department of Transportation history.

WSB’s Jennifer Perry contributed to this story