Nearly two decades after it was first proposed, the interchange reconstruction project at Flat Shoals Parkway and I-285 in Atlanta is now complete. The new interchange was opened to traffic in early January, and remaining final touches were recently finished. 

The massive Georgia Department of Transportation (GDOT) project, designed to help improve traffic flow and mobility in and around the heavily traveled interchange, and originally slated for completion in the fall of 2017, has been a source of challenges to the GDOT and its contractors, and area residents. Since the January 2015 groundbreaking, there have been 18 months of delays primarily associated with previously unidentified utilities, which required relocation, adding $3 million to the total cost.

Interstate 285, which loops around Atlanta, connects the three major interstate highways to the city – I-20, I-75, and I-85. It is estimated that more than 2 million people use the highway each day, making it the busiest Interstate in the Atlanta metropolitan area, and one of the most heavily traveled roadways in the United States. Due to this heavy volume, during peak commute hours portions of the highway often slow to a crawl.

The I-285/Flat Shoals project reconstructed the interchange of I-285 with SR 155 in DeKalb County; included in the project was the replacement of the SR 155 Bridge over I-285 and jacking the existing Panthersville Road Bridge over I-285. Both these structures were deemed to provide substandard vertical clearance for large vehicles traveling along I-285. Additionally, an increase in commercial development along the SR 155 corridor has resulted in poor traffic operations in the interchange area; industrial park and residential development also continues to grow – as does the population. Along the corridor, traffic demand has grown substantially over the years, and had far exceeded the capacity of the existing interchange. Average annual daily traffic volume has been projected to be over 59,000 vehicles on Flat Shoals Road and over 214,000 vehicles on I-285 by the middle of the next decade.

Tori Brown, District 7 Communications Officer for GDOT, provides an overview of the project's scope: “The bridge carrying Flat Shoals over I-285 was replaced, all four ramps were lengthened and widened, barrier walls, retaining walls, and sound walls were constructed where warranted, major utility relocation was required, traffic signals were replaced, and pedestrian signals were added.  Medians were also constructed in the vicinity of the ramps to reduce conflicts caused by turning movements, thereby improving both the safety and operational efficiency of the interchange.

“This is a major reconstruction of an interstate interchange in metro Atlanta, and about a $48 million infrastructure investment in a community that hasn’t seen a comparable, significant project in decades,” Brown continues. “Population, businesses and visitor attractions have grown exponentially in DeKalb County.  Traffic congestion and delays, and traffic-related accidents, have been a major problem for commuters and for commerce, with negative impacts on work productivity.” 

Specifically, in addition to the new bridge, components of the reconstruction project include the construction of two through lanes and bike lanes in each direction; construction of dual, left-turn lanes from SR 155  (northbound/southbound) onto I-285 (eastbound/westbound); widening of interstate exit ramps to provide dual left and right turn lanes onto SR 155; and the construction of noise walls under the Panthersville Road Bridge at I-285 to allow the ramps to be extended under the bridge.

GDOT employees designed the project in-house, and Pittman Construction Company was the primary contractor. Established in 1884, Pittman Construction is one of Atlanta's oldest construction firms, and has worked on numerous Interstate 285 and Interstate 75/85 projects. 

Unexpected Utility Issues Caused Project Delays

The Right-of-Way process for the project was completed during 2012, followed by preliminary engineering work in 2013, and the start of construction at the beginning of 2015. Not long after construction got underway, however, work on the project slowed down drastically, and at times stopped altogether, due to unexpected issues with water lines that serve the area – including one running adjacent to Panthersville Road and another underneath I-285. Many months of expensive and lengthy project redesigns were required in order to resolve the problems without impacting water service to the surrounding community.

As Brown relates, “Georgia DOT contractors began work on the project in January 2015 and were scheduled for completion in September 2017. However, early in the construction phase, work crews were challenged by the discovery of an undisclosed water main line in the project area that had to be carefully relocated to avoid service interruption to homes and businesses in the area. 

“Encased, the water main was 5 feet in diameter and was raised up at approximately 45 degrees.  After a lengthy environmental review to avoid a stream and requisition of specialized equipment, crews tunneled the large water main under six lanes of I-285 to relocate it.

“The processes of redesigning the water line, acquiring environmental approvals to replace it and the method of micro-tunneling the waterline under I-285 added approximately 18 months to the timeline of the project.”  

GDOT Public Outreach Efforts Address Concerns of Residents

Area residents and business owners grew increasingly frustrated by the project's slow progress. Residents often questioned why the I-285/Flat Shoals project could not be completed as quickly as recent I-85 bridge replacement projects.  As pointed out by GDOT, however, there were many factors that affected the timeline of the interchange project:

• Because of the Governor’s declaration of a state of emergency, work on the I-85 bridge replacement was allowed on a 24-hour a day, seven-day a week schedule
• The I-85 bridge replacement did not require underground construction
• The I-85 projects did not encounter unanticipated utility conflicts 
• The I-85 project was completely closed to traffic, eliminating the need for traffic control measures
• The I-285/Flat Shoals interchange project incorporated a new, wider bridge with a different footprint than the structure it replaced, while the I-85 bridges kept the same footprint

During the long gestation of the Flat Shoals interchange undertaking, GDOT made extensive outreach efforts to alleviate residents' concerns and keep the public updated, says Brown.  These efforts include meetings between community groups and GDOT officials, open houses where project specifications and renderings were presented, quarterly GDOT meetings to provide updates on the project, and regular news releases highlighting project milestones. Additionally, an extensive project website included project maps and renderings, a frequently asked questions section, informational flyers, and ongoing project reports. 

Critical to the progress of the extensive undertaking was management of a very large volume of traffic through the interchange area, says Brown. “Traffic shifts were required to keep the lanes open during construction. There were nighttime and weekend closures; these closures were communicated via press alerts and social media. At least one lane of traffic was maintained in each direction throughout the construction process.” 

An Improved Driving Experience

With its progress delays and traffic impacts, the interchange reconstruction project at Flat Shoals Parkway and I-285, underway in some manner since the early 2000s, has caused concerns among area residents.  However, now that it is completed, the reconstruction promises to at last bring motorists along the corridor a much-improved driving experience.  As Brown states, “Our goal with this major investment is to help ease traffic congestion for the growing trucking logistics industry in DeKalb County and throughout the state, as well as for work day commuters, visitors, and tourists. The significance of this project in South DeKalb is primarily that it will enhance both mobility and safety for the traveling public in DeKalb County and the Atlanta region.”

Brown adds that the magnitude and scope of this project attracted the interest of local elected officials during construction. The final closeout for the reconstruction project took place in February.