Commuters who travel the I-285 and Ashford Dunwoody Road interchange may soon experience a new traffic concept: the diverging diamond interchange.

The Georgia Transportation Infrastructure Bank last week awarded an $800,000 grant to the Perimeter Community Improvement District to help fund the concept’s design. If built, the interchange will follow one in Springfield, Mo., as the only two in the United States.

A statement issued by Gov. Sonny Perdue’s office said the project was chosen because, “The DDI would provide additional capacity without reconstructing new lanes by restriping, altering signal timing, improving turning conditions and reconstructing a ramp.”

The new type of interchange would require drivers to cross briefly to the other side of the road. Those turning left onto the interstate would be able to do so without crossing oncoming traffic.

David Haynes, short range programs manager for the Atlanta Regional Commission, said, “What it essentially does, as you go across the bridge you flip the lanes on the left side and instead of a left turn on the ramp there’s a free flow left turn.

“It’s worked really well in Missouri, and conceptually it makes a lot of sense. I think it will take a little getting used to for people to know they’re on the wrong side of the road and it’s OK,” he added.

Yvonne Williams, president and CEO of the Perimeter Community Improvement District, said the interchange could be in place by the beginning of next year.

“It’s not a massive project in that it won’t majorly disrupt traffic,” Ms. Williams said.

Ms. Williams estimated the design for the interchange will cost between $700,000 and $800,000. Its construction may be around $6 million, with all funding coming from the state, she said.

A total of 52,400 vehicles per day passed through the interchange in 2009, according to the Perimeter CID .

Ms. Williams’ organization began work with a consulting firm over a year ago in search of a plan to alleviate traffic congestion at the interchange, she said.