To tear down and replace the bridge over Abernathy Road, crews will have to close Ga. 400 from Hammond Road to north of Abernathy Road, state transportation officials told the Sandy Springs City Council on Thursday.

Representatives from the Georgia Department of Transportation (GDOT) attended the council’s annual retreat on Feb. 3, sharing updates on projects including Transform 285/400. 

Bridge construction at Abernathy is expected to take four months after the existing bridge is torn down in March. With that section of Ga. 400 closed, vehicles will be diverted to the collector-distributor (CD) lanes already constructed north and southbound.

Northbound traffic on Ga. 400 is expected to shift onto those new CD lanes starting at Hammond Drive on Feb. 13, Marlo Clowers, a GDOT program manager, told the council. It will merge back onto the highway north of Abernathy. Motorists leaving Hammond Drive to head north on Ga. 400 also will use the CD lanes.

“The purpose for doing that is to get this traffic away from the existing Ga. 400 bridge over Abernathy Road, so that that bridge can be replaced,” Clowers said.

A similar shift will happen for southbound Ga. 400 traffic, which will merge onto CD lanes north of Abernathy Road. The CD lanes were built to access the new Hammond Drive off-ramp and the Abernathy off-ramp.

The project also includes construction of the Abernathy Road double diamond intersection, which GDOT anticipates will begin in March 2022. Once completed, the intersection should improve the flow of traffic and increase left turn capacity, Clowers said.

“We’ve opened some of the ramps already but a lot of the work on the actual Abernathy roadway will start in March, along with the demolition of the existing bridges. So once we get the traffic shifted in February, we’ll have that existing bridge there that we can then take down and rebuild up,” she said.

She told Mayor Rusty Paul that there could be some extended lane closures, with traffic rerouted to other roadways in the area to get in and take the bridge down quickly and safely.

“That’s something we need to get out there well in advance because that’s a major connecting point between Cobb County and then the Perimeter job market,” Paul said.

Private developers to build, operate Express Lanes

GDOT is shifting its plan for the construction and operation of express lanes on I-285 and Ga. 400, north to the North Springs MARTA station, said Tim Matthews, GDOT’s Express Lanes administrator.

A private developer will be under contract to design, build, finance, operate and maintain the toll lanes. This will enable 21% more lane miles, he said.. In return, the developer will collect the toll payments for an extended period, usually 50 years in these kinds of agreements, Matthews said.

This model will enable a second express lane to be added on I-285’s east and west sides.

“We could only afford in the previous model one lane in each direction,” Matthews said. 

Three bridge replacements on Ga. 400 in North Fulton – including those at Pitts Road and Roberts Drive in Sandy Springs – were pulled into a Phase 1 of the Express Lanes project. This was done to enable GDOT to keep and use $185 million in grant funds that must be used under deadline, Matthews said.

Construction on the bridges is expected to start in 2023. The bridges will have raised profiles to accommodate express lanes in the future.

GDOT has discussions with local police, fire and school systems so they can make plans for service during the bridge closures, he said.

Bus rapid transit stations are still planned along Ga. 400. The buses would use the express lanes.

Bob Pepalis

Bob Pepalis covers Sandy Springs for Reporter Newspapers.