The State Transportation Board signed off Thursday on a $685.5 million plan to redesign the interchange of interstates 285 and 20 east of Atlanta.

The board voted to begin negotiations with one of three roadbuilding consortiums selected from a shortlist of competitors to build the project. Construction is due to begin in the middle of next year and be completed by late 2026.

The consortium East Interchange Builders scored tops in the competition, both for the technical and financial aspects of its proposal, Meg Pirkle, chief engineer for the Georgia Department of Transportation (DOT), told board members. The lead partners are Archer Western Construction and E.R. Snell, two of Georgia’s leading highway contractors.

The frequently congested interchange on the east side of metro Atlanta’s Perimeter Highway in DeKalb County was ranked as the nation’s 25th worst bottleneck last year.

The overhaul will include reconstructing ramps to create more direct alignments, adding new collector-distributor and auxiliary lanes, replacing several bridges and erecting new noise barriers.

The work will be done through a design-build-finance contract, the same model that was used to build the Northwest Corridor toll lanes along I-75 and I-575 in Cobb and Cherokee counties and in the redesign of the I-285/Georgia 400 interchange, which is still under construction.

“We got three tremendous responses,” said board member Kevin Abel, chairman of the steering committee that oversaw the competition. “This is a great procurement we hope will repeat for the upcoming even more massive procurements [the DOT] is going to be taking on in the next couple of years.”

Under the design-build-finance contract model, the State Road and Tollway Authority will finance the project, while the DOT will manage the work.

This story is available through a news partnership with Capitol Beat News Service, a project of the Georgia Press Educational Foundation.

Dave Williams is the Bureau Chief of Capitol Beat News Service.