A diverging diamond interchange (DDI) is an innovative traffic solution designed to increase capacity, decrease congestion at intersections while minimizing cost. The DDI is designed to ease the flow of heavy traffic by eliminating a left turn signal, and allowing two directions of traffic to cross the opposite side of the side or cross street at or near the bridge point over the freeway. A simulation showing how the completed project will operate can be found here (requires Silverlight plugin, if not already installed).
Cobb County will be responsible for completing and funding the preliminary engineering and right-of-way costs for the project. Once completed, GDOT will fund up to $1 million of construction costs from their operational improvement lump sum. The rest of the $1.625 million cost will come from Cobb County SPLOST funds.
The proposed project is one of several planned diverging diamond interchanges in the Atlanta Region. Georgia’s first diverging diamond interchange at I-285 and Ashford-Dunwoody Road in DeKalb County opened to traffic in July 2012.