President's Perspectives


Georgia’s first Diverging Diamond Interchange at I-285 at Ashford Dunwoody Road is an example of the public-private cooperation that will be critical for moving transportation projects forward in Georgia in the future, Lt. Gov. Casey Cagle said at the dedication and celebration of the project’s completion on November 16, 2012.

Speaking atop a grassy hill overlooking the interchange, Cagle noted the switch in traffic in a DDI from the traditional U.S. drive-side right lanes to driver-side left lanes to reduce points of traffic conflict and improve traffic flow and safety.

“This innovative project is a testament to the drive and dedication of the Perimeter Community Improvement Districts to improve traffic congestion in the important Perimeter Market and to the Georgia Department of Transportation for being receptive to creative, low-cost ideas to meet traffic challenges,” Cagle said.

The $6 million DDI was initiated in 2009 by the PCIDs to improve the more than 40-year-old interchange, which was inadequate to serve the nearly 55,000 vehicles that use it daily, said PCIDs President and CEO Yvonne Williams. The PCIDs hired Moreland Altobelli engineering firm to find an immediate, low-cost way to make improvements, Williams said. The firm recommended the cutting-edge DDI design, which originated in France and had first been used in the U.S. in 2009 in Springfield, Mo.

DDI Group Photo
PCIDs Partners celebrate the dedication of Georgia's first DDI on November 16, 2012

The PCIDs received grant funding from the State Road and Tollway Authority and DeKalb County for engineering and design and Williams said “GDOT quickly came on board with the project and funded the $4.6 million cost of construction.”

While traffic studies won’t be completed until the spring, Cagle said early reports and commuter feedback indicate that congestion and accidents are improving significantly at the heavily traveled entrance to the Perimeter Market.

Williams gave credit at the dedication to GDOT Commissioner Keith Golden and to GDOT Chief Engineer Gerald Ross, who gave the DDI idea to Moreland Altobelli. She also thanked other GDOT staffers who worked on the project, contractor E.R. Snell, who “constantly met or exceeded our expectations,” Moreland Altobelli for “good engineering and design work” and the Federal Highway Administration, “whose involvement from the beginning was crucial to the quick turnaround of the project.”

Dunwoody Mayor Mike Davis, who was excited to be in the first car to drive across the bridge when it reopened to crossover traffic, said the city is proud to showcase Georgia’s first Diverging Diamond Interchange.

DDI Arial Photo
View of Georgia’s first Diverging Diamond Interchange headed north

“The DDI helps continue the transformation of Perimeter from a traffic-clogged market into an award-winning, sustainable model community,” said DeKalb PCID Vice-Chair Kay Younglove, a senior vice president of Jones Lang LaSalle, who has leased office buildings in the Perimeter market during the last 30 years. “Companies want to locate and expand in a centralized area with good transportation infrastructure that provides access and connectivity. Improvements like the DDI continue to make Perimeter an obvious choice.”

“The economic health of the Perimeter Market is important not only to the businesses and cities located in this area, but also to local and state government that depend on the tax revenues generated in the Perimeter area,” Cagle said.

Commercial real estate developer Bob Voyles, one of the founders of the DeKalb PCID, recalled how the interchange looked in 1992 when he and his boss then at Hines took former DeKalb County CEO Levetan to the top of the Crown Plaza Hotel to see how bad the traffic was during rush hours.

“Traffic issues were starting to become a major problem then in Perimeter, said Voyles, who has developed property in the area over the years for Hines and now for his own company Seven Oaks.

“The interchange needed to be redesigned and revamped. It hadn’t been maintained since the early ‘60s when the bridge was added,” said Voyles. “Kudzu and construction trash were everywhere. The front door to the most expensive office space in DeKalb County was horrible.

“Today, you see a great example of Perimeter’s transformation,” Voyles said. “The front door to Perimeter in DeKalb County is a showplace for transportation design and will be further enhanced with beautiful landscaping in the spring.”