Big plans for Ga. 400/I-285 interchange just got bigger

What’s next?

  • The Georgia Department of Transportation will make a public notice announcement, which informs potential contractors about the project, in October or November.    
  • A Request for Qualifications from interested contractors would be issued by mid-2015, which would help GDOT narrow down the list of potential bidders for the work.
  • A Request for Proposals from approved contractors would be issued several months later.    
  • Construction would likely begin in 2016 and the interchange would open to traffic in 2019.    

A tale of two interchanges

Ga. 400 & I-285/ Spaghetti Junction (I-85 & I-285)

Opening year: 2019 / 1987

Cost to build: $950 million (early estimate) / $71.6 million

Number of bridge levels: four/ five

Number of acres: To be determined / Total bridge area covers 18 acres, total interchange area is 311 acres.

Number of bridges: Probably 10 to 12, depending on contractor’s final design / Six major bridges and eight minor bridges

Maximum height: To be determined / 90 feet

Traffic comparison for interchanges along I-285

Ga. 400 416,000

I-85 North (Spaghetti Junction) 421,043

I-85 South (south side) 274,198

I-75 N (Cobb cloverleaf) 411,960

I-75 S (south side) 249,955

I-675 190,491

I-20 E (east side)294,721

I-20 W (west side)291,914

(Total sum of traffic in all four directions)

Imagine the artfully contorted whorl of concrete that is Spaghetti Junction, transported nine miles to the west. That should give you some idea of the state’s plans for the revamped Ga. 400/I-285 interchange.

Now imagine three years of construction on one of the busiest stretches of road in Atlanta. That should give you some idea of the traffic nightmares that lie ahead.

The Ga. 400/I-285 rebuild, meant to ease traffic for 416,000 drivers a day, has always been a big undertaking. But in exclusive interviews, The Atlanta Journal-Constitution discovered that the project has morphed far beyond its original scope — to the possible delay of other projects in coming decades.

State leaders have latched on to a truly mammoth version of the concept, one that would add miles of lanes adjacent to both major highways and consume an amount almost equal to the state’s entire annual road construction budget.

At an estimated cost of $950 million, it would be the most expensive road project in state history, paid for by going at least $130 million into debt, not counting interest costs. It would take three years of heavy construction to build. And after it is completed in 2019, the debt payments could eat into the state’s regular construction budget, forcing other road projects to be put on hold.

Nevertheless, state officials believe the expanded version is worth the cost, because the result could transform traffic on the top end of the Perimeter. Both Gov. Nathan Deal and the Georgia Department of Transportation have labeled the congested interchange the state’s highest priority road project.

“It’s a tremendous undertaking,” said Michael Hunter, a professor of civil engineering at Georgia Tech who reviewed the conceptual design at the AJC’s request.

Sabine Charles is among the hundreds of thousands who will welcome a fix to the interchange. The Douglasville resident paused last week outside a Whole Foods off Roswell Road to contemplate the sprawling project. Charles said she often shops near the Perimeter and finds the traffic exhausting. Although things will worsen during construction, “after that, people are going to get relief,” she said.

Last month the State Transportation Board vote to accelerate the project by selling $130 million in bonds and using $81.5 million in motor fuels tax revenue. The state will also ask the developer to front some of the construction costs, creating even more debt.

Recently, the state’s chief traffic engineer detailed the state’s plans in an exclusive interview with the AJC.

The new interchange would resemble the I-85/I-285 interchange, better known as Spaghetti Junction, with soaring flyover bridges curling around one another. However, it will occupy a slightly smaller footprint, according to GDOT’s chief traffic engineer Russell McMurry. It would also have four levels of bridges, as opposed to Spaghetti Junction’s five.

But it’s not enough just to fix the interchange. State officials say the boundaries of the project will need to stretch miles in every direction to have an impact.

“If you just go in and correct the interchange itself, you’ll be sitting on a nice bridge looking at the same congestion,” McMurry said. “To make everything work now and for a long time it takes a really big project, with improvements on 285 and 400 radiating out from that interchange.”

To that end, two-lane access roads will also be constructed along four miles of I-285 from Roswell Road to Ashford-Dunwoody Road; and along two miles of Ga. 400 from Glenridge Connector to Spalding Drive.

These roads would run parallel to the interstates but would be separated by a concrete barrier, much like the access roads alongside I-85. Traffic coming off the interstate ramps and nearby exits would enter these parallel lanes before getting on the highway. Much of the merging and weaving that tends to slow down freeway traffic would occur on the parallel roads, keeping the main lanes free-flowing.

There are numerous examples of this type of interchange across the country nowadays, but every design has its own unique challenges, Hunter said. “That’s an impressive interchange,” he said of GDOT’s expanded design.

If all goes as planned — never a given with highway projects, especially ones of this magnitude — construction will begin in 2016 and the redesigned interchange will open in 2019.

That’s an ambitious construction schedule, considering it took two years to build the I-85/Ga. 400 ramps in Buckhead — a considerably less complex undertaking. That project was completed four months late due to weather delays.

GDOT says it will be looking for one development team that can design, build and help finance the project. That’s a new approach for Georgia, which the state is piloting with the express toll lanes soon to begin construction along I-75/I-575. In other states, combining those functions instead of contracting them out separately has been shown to deliver projects more quickly.

Before construction can start, GDOT will need to acquire about 80 parcels of land in an area that is densely packed with businesses, homes and warehouses. The project also must overcome federal environmental hurdles and engineering studies that are supposed to be completed next year.

On past projects, GDOT has had trouble finishing preliminary studies and design on time. But once a contractor broke ground, the agency has a very good track record for finishing construction on schedule.

As for the headaches construction will bring, GDOT Commissioner Keith Golden said that the public will probably have to contend with evening and weekend lane closures, perhaps even occasional workday lane closures. But he said much of the work can be done outside of the lanes of traffic.

The department will do everything it can to minimize the impact on motorists, he said.

“It’s painful to get there,” Golden acknowledged. “But you’ve got to start, or you’ll never get there.”

The interchange is long overdue for an overhaul, said Steve Williams, who writes “The Georgia Road Geek” blog.

“I am quite surprised that GDOT did not start working on a redesign and build it before Dunwoody, Sandy Springs, and vicinity really began to grow,” Williams said in an email.

Indeed, the area around Sandy Springs and Dunwoody is already exploding with development. Major corporations like State Farm, AirWatch and Cox Enterprises, parent company of the AJC, have expanded their presence in the Perimeter area the past few years. And State Farm will soon add 2.2 million square feet of office space in a complex that broke ground off Hammond Drive last month.

Thousands of apartments are also under construction or on the drawing board, and the Atlanta Regional Commission projects that the Dunwoody-Sandy Springs area will add more than 20,000 residents between 2010 and 2020.

Spaghetti Junction provides a preview of what commuters can expect. In the 27 years since it opened, the interchange has become mired in the same gridlock purgatory that plagues much of the Perimeter during rush hour. But it did provide major congestion relief for area commuters when it opened, replacing an antiquated cloverleaf interchange. The AJC at the time ran headlines like “Superlooper takes snarl out of traffic” and stories that declared “it works.”

The new Ga. 400/I-285 interchange will fill up again, too, if the region grows as expected. Running just to catch up is the reality of modern-day road planning in urban areas. But users will enjoy the benefits of the redesign for many years, said Golden.

News of the impending interchange redesign — and requisite road work — has been met with both hope and apprehension by area drivers and business owners.

At the Pit Stop Barber Shop off Roswell Road, owner Chase Alford frowned at the prospect of construction-related slowdowns and lane closures.

“While they are doing the construction, it’s actually going to hurt us, because people are going to have a hard time getting in here,” Alford said.

Over on Ashford-Dunwoody Road, LifeLine smartphone repair shop manager Dru Jamieson said congestion gets so bad that very few customers care to frequent the store between the hours of 3 and 5 p.m. He said the state’s plan to add an access road at Ashford-Dunwoody might improve traffic in the long run. But he’d rather see the money go to MARTA.

“If we would put close to a billion dollars toward mass transit, I think we would see much better access to this area as a whole — more stops and more trains,” Jamieson said.

James Tom, an executive who commutes from Lawrenceville to the Perimeter business district, wasn’t eager to endure the construction phase, but he did see a light at the end of that long tunnel: “I guess once it’s finally done, it’s gonna be great.”