The interchange bridge will be closed for removal of asphalt, construction of a pedestrian walkway, paving, restriping and installation of traffic signals beginning at 9 p.m. June 1 and reopen June 4 at 5 a.m. for crossover traffic.
“We are looking forward to reaching this milestone in the project schedule and even though we are shifting traffic into its final alignment, motorists need to understand that construction will be continuing out there for the next three months,” said GDOT District 7 Engineer Bryant Poole.
PCIDs president and CEO Yvonne Williams said the low-cost, creative DDI design has been used successfully in four other states to improve traffic congestion and that commuters, visitors and residents in the central perimeter market are expected to see a major improvement as well.
When the crossover begins, traffic on Ashford Dunwoody Road will cross from the right side of the roadway to the left side at a ramp intersection signal so vehicles may make free left turns onto the I-285 freeway on-ramp. Traffic will then cross back to the right side of the road at a second ramp intersection. A loop ramp used to access I-285 East from the interchange bridge that has been a major contributor to the congestion in the corridor will be removed.
Only the bridge ramps will be open during the weekend bridge closure and traffic will be detoured through the I-285 Perimeter Center Parkway “flyover” bridge. Pedestrian traffic will not be allowed on the bridge during the month of June while a pedestrian walkway in the bridge median is completed. The walkway is being placed inside a concrete barrier-protected pedestrian only zone.
“When the bridge opens to crossover traffic, signage, lane striping and curbs will be in place to guide and safely separate opposing traffic as it moves through the interchange,” said PCIDs Chief Operating Officer David Purcell. “Police officers also will be on duty at the interchange throughout the weekend and after the bridge reopens to assist motorists with the new configuration.”
The DDI design was originally used in France and spread to the U.S. in 2009 when the first such interchange was built in Springfield, Mo. The PCIDs initiated the Dunwoody project when they hired Moreland Altobelli Associates to find an interim solution for the busy I-285 and Ashford Dunwoody Interchange — a gateway to central perimeter, metro Atlanta’s dominant office market and one of the region’s largest employment centers.
The PCIDs then received funding from DeKalb County and the State Road and Tollway Authority for engineering and project design. The Georgia Department of Transportation is funding the $4.6 million construction cost.
“We’re expecting that under normal, free-flowing traffic conditions on surrounding highways, the I-285 and Ashford Dunwoody DDI will reduce traffic delays in evening rush hours up to 20 percent,” Williams said. “There are significant safety improvements also with DDIs,” Williams said.
To view a simulation of the I-285 and Ashford Dunwoody Interchange DDI, visit www.perimetercid.org or www.canyouddi.org.