I-285 at Ga. 400 work nearly done - but more construction on the way

“It’s like dominos,” GDOT spokeswoman Natalie Dale said. “As you finish one (project), the next one is set up to fall.”

Still, the I-285/Ga. 400 interchange is a mighty big domino.

More than 400,000 vehicles pass through the junction of the two highways north of Atlanta each day. But the original interchange was designed to accommodate only 100,000 vehicles, and it had become a massive traffic bottleneck.

Major work began on a new interchange in November 2017. The design featured new flyover ramps and additional lanes to take traffic off both highways. It also included a new diverging-diamond interchange at Ga. 400 and Abernathy Road and other work.

The interchange was originally supposed to be finished in 2020. But the scope of the project grew to include new bridges on I-285 and repaving part of the Perimeter. Unmarked utilities, poor weather and COVID-related staffing and supply chain issues also led to delays.

The cost of the project also grew from an estimated $800 million to about $922.5 million, Dale said. That includes the cost of three new bridges and the repaving on I-285, which were not originally part of the project. In both cases, Dale said GDOT decided to do the additional work while the area was already under construction instead of waiting until later.

The construction zone stretched for miles along I-285 and Ga. 400. Much of the work was done at night, but daytime traffic jams were common – and sometimes made worse by truck crashes and other mishaps.

As the years passed, GDOT opened new ramps and lanes as they were completed. The last major piece of the puzzle fell into place on May 8, with the full opening of a bridge from the Glenridge Connector to I-285 westbound and Ga. 400 southbound.

With the work nearly done, GDOT says traffic through the interchange has improved.

According to a GDOT report, southbound traffic on Ga. 400 moved at an average speed of 33 to 39 mph during morning rush hour in 2014. Recently, the average speed has been 50 mph.

Ann Hanlon, executive director of the Perimeter Community Improvement Districts, has noticed the improving traffic. She said years of construction have taken a toll on area businesses and their employees.

But Hanlon said the new interchange has given companies confidence to invest in the area. One example: Newell Brands recently signed a 180,000-square-foot lease at the iconic Queen building in Sandy Springs. It’s the largest lease signed in the Central Perimeter area since 2018.

“That’s kind of a barometer of success for us,” Hanlon said. “We are seeing companies continue to choose this area and stay in the area because this (interchange) investment has been made.”

Some work on the interchange project continues. The contractor - North Perimeter Contractors - must still finish paving and striping on I-285, install overhead message boards and ramp meters and perform other tasks. That means lane closures will continue.

What’s more, the interchange isn’t the only road work in the area. GDOT plans to add toll lanes to the top half of I-285, and work has already begun on a top end auxiliary lane associated with that project.

The agency also plans to add toll lanes along 16 miles of Ga. 400. GDOT expects to award a contract for that work in August, with work starting about a year later.

In short, commuters are not likely to escape construction-related delays in the area, at least for long. But Dale said each project is the solution to a specific problem.

“There will be many benefits to the top end (of I-285),” she said. “But there will be continual work.”