The Northwest Corridor Express Lanes project is the largest project in the Georgia Department of Transportation’s history and includes 29.7 miles of reversible tolled express lanes along I-75 and I-575 in metropolitan Atlanta. The reversible toll lanes extend northwest along I-75 from I-285 to Hickory Grove Road and along I-575 from the I-75/I-575 interchange to Sixes Road.
The project includes the design of six new express lane interchanges on I-75; three new access points along I-575; and 39 bridges, totaling 5.2 miles with over 1 million square feet of bridge deck supported by 195 intermediate bents and 772 prestressed concrete beams. The project included more than 100 retaining walls up to 45 feet in height with a combined length of 10.5 miles. There are approximately 1.4 million square feet of noise barriers, 640,000 square feet of mechanically stabilized earth (MSE) walls, and 261,000 square feet of soil nail cut walls.
A First in Georgia
The Northwest Corridor Express Lanes project is the first design-build-finance project awarded by GDOT and the first time GDOT has partnered with private industry to deliver new infrastructure. The uniqueness of the project delivery, the size of the project, and the location in metro Atlanta presented challenges, including maintenance of traffic during construction in this urban corridor. Through close coordination with the owner and innovative design and construction techniques, such as accelerated bridge construction (ABC), the team overcame these challenges. The design-build process accelerated project delivery by 10 years and reducing costs to $110M under GDOT’s budget. Beyond the cost and schedule outcomes, the project has had a positive impact on the community and region, reducing one-way commute times by as much as 45 minutes and spurring the growth of the local economy.
Design-Build Team
| Client/Owner: | Georgia Department of Transportation |
| Design-Build Firm: | Northwest Express Roadbuilders |
| Engineer: | Parsons Transportation Group Inc. |
| Specialty Contractors: | Moreland Altobelli Associates, Inc. |
| Project Manager: | Archer Western Construction |
| Construction Duration: | 64 Months |
| Project Cost: | $647,166,673.00 |
Photo Credit: © Aerial Innovations of Georgia, Inc.