A ceremonial groundbreaking for the I-285/Ga. 400 interchange reconstruction project is slated for Nov. 3, according to the state Department of Transportation. But early preparation work is already underway, but major construction affecting traffic likely won’t begin until late February, according to GDOT spokesperson Jill Goldberg.

The groundbreaking will feature Gov. Nathan Deal and GDOT Commissioner Russell McMurry, among other officials. Its location is still to be determined, according to Goldberg.

A GDOT illustration of the future rebuilt I-285/Ga. 400 interchange

The contracting team on the project, North Perimeter Contractors, is currently conducting surveying and exam work such as inspecting storm drains and culverts, Goldberg said. GDOT expects to issue this week a “notice to proceed” allowing actual construction work.

“It’s not going to be the kind of stuff where you’re going to see massive cranes and roads being torn up,” she said, adding that level of work is likely months away.

Besides rebuilding the interchange to improve traffic flow and capacity, the project will add “collector-distributor lanes”—physically separated exit and entrance lanes—to Ga. 400 north to Sandy Springs’ Spalding Drive and to I-285 between Sandy Springs’ Roswell Road and Ashford-Dunwoody Road in Dunwoody and Brookhaven. The Ga. 400/Abernathy Road interchange in Sandy Springs will be rebuilt as a “diverging diamond,” in which traffic flow changes in time with traffic lights to move cars faster.

When construction starts, it will happen in phases and stages that will last more than three years, into mid-2020.

Where exactly work will begin is still up in the air. “They have not made a decision,” Goldberg said of the contractors, though there is talking of starting with rehabbing or reconstructing bridges over Ga. 400, which includes the Mount Vernon Highway bridge.

The interchange project’s major work will start around the same time that another big traffic impact is coming to the Perimeter: the new Atlanta Braves stadium in Cobb County. Goldberg said GDOT is not specifically coordinating the interchange work with Cobb or the Braves, but is generally aware of stadium parking and traffic planning.

GDOT met Sept. 14 with local cities’ police, fire and rescue officials as an introduction to coordinating planning on how emergency vehicles will get through the interchange construction areas, Goldberg said.

GDOT and the contractors will both have a hands-on command center near the heart of the project as they will operate offices on Carpenter Drive in Sandy Springs, just a block north of I-285. That means project officials will be driving through local traffic, too—and Carpenter Drive itself is due for a significant intersection reconstruction project in coming months.

“We don’t escape [traffic impacts],” Goldberg said. “Welcome to the neighborhood, right?”