Georgia DOT Speeds Traffic With SR 400 Widening
As soon as the first segments of the Georgia Department of Transportation’s (GDOT) $47 million widening of State Route 400 north of Atlanta opened, drivers saved significant time on their drives to and from the city.
“This is my commute, and when we opened the first 8-mile segment, I saved 25 to 30 minutes in commuting time,” said Rick O’Hara, Project Manager for GDOT. “It was instantly faster, the day it opened.”
It’s the anticipation of that sort of time savings that prompted voters in Forsyth County to approve an up to $200 million general obligation bond to fund transportation improvement projects. This SR 400 widening was at the top of the list.
A Partnership for Improvement
“Our citizens recognized the need to continue to enhance transportation in our county and they decided to do something about it,” said County Commission Chairman R.J. (Pete) Amos, at the groundbreaking of the SR 400 project. “By approving Forsyth County’s Transportation Bond, they enabled the county to advance projects sooner than otherwise would have been possible, while leveraging state and federal funding, making the most of our bond dollars.”
The county partnered with GDOT to build the additional lanes. Initial cost estimates were for $63 million. Andrew Hoenig, Senior Project Manager at GDOT, said this was the first time the department has worked with a local government in this way.
The department has additional projects planned that will partner with local governments. GDOT Spokesperson Natalie Dale, says that the process has saved time and money by using creative building and financing methods.
“It’s a great example of what you can get done when you have a perfect storm of financing and innovation,” Dale says.
GDOT decided to let the project using the design-build delivery method to speed completion, so county residents could see the benefits from passing the referendum as quickly as possible. The department let the job using a variable-scope procurement approach, with 10 different segments, not sure if it had the funds to complete the entire project.
A team of C.W. Matthews Contracting Co. of Marietta, Georgia, and Infrastructure Consulting & Engineering of Columbia, South Carolina, received the contract with a bid of $47 million for the entire 13.8 miles, with a requirement to break ground by November 2015, about one year after the voters passed the referendum. That Matthews bid was $16 million less than the department estimated for the entire job. Money for the project included $34 million from the bond program and $13 million from GDOT
“We got every segment and capitalized on the time, so absolutely we are pleased we went with design-build,” says Hoenig.
The money saved helped expedite a project converting the grade separation of the SR 400/Interstate 369 intersection to an interchange, which is programmed by GDOT and the locals to start after the SR 400 is complete.
The 13.8-mile SR 400 project involves building one northbound and one southbound lane in the median of the existing four-lane, limited-access highway from the McFarland Road exits to SR 369/Browns Bridge Road. The road will carry 112,000 vehicles per day in 2020 and 140,000 in 2040. Most of the new road is concrete to match the existing corridor and the last mile has asphalt paving. The new lanes will be toll-free.
The project includes widening two bridges, both employing concrete girders. One bridge was over Big Creek and a greenway, walking trail at the southern end of the project, and another was over the Sawnee Creek portion of Lake Lanier at the north end.
“We knew the bridges would be critical paths to open the road,” Hoenig recalls.
The department obtained environmental and U.S. Army Corps of Engineers’ approval as fast as possible. The Corps owns Lake Lanier. The first bridge was started quickly and completed before the paving, Hoenig says. The second bridge required some dredging, performed with equipment on site and the Corps’ permit. Also speeding construction was that the department did not need to purchase right of way.
Constructing South to North
Matthews began the job on time, working from south to north to provide the greatest affect on reducing congestion. The southern portion is closest to Atlanta. Traffic drops off the farther north motorists drive. The department required the contractor to open each 4-mile segment it completed as that portion of the work.
“We did not want people to see a segment of concrete sitting there and not open,” O’Hara says.
The department also required the contractor to work on weekends, from Friday through Monday morning. Matthews completed the grading in the evening and come nighttime was ready to pave. Matthews has been paving a mile per weekend.
“It condensed the time for construction, and increased the efficiency,” Hoenig says.
The concrete plant is nearby and Matthews has been transporting the concrete in dump trucks, to get a quick turnaround time. Construction has progressed smoothly. The project remains on budget and on time, even with the contractor diverting some crews to help with the emergency replacement of Interstate 85, after a major fire caused an elevated section of the road in Buckhead to collapse.
Throughout construction, GDOT has worked to keep the public informed about progress and targeted opening dates, O’Hara says.
The northbound lanes opened in 2017 and the southbound lanes are on track to open in spring of 2018. No concrete paving will take place during the winter. As segments are complete, Matthews and GDOT will open that segment. Additional shoulder rehabilitation work may take until October 2018.
“This is the highest profile project of the $200 million,” says Hoenig. “This is the biggest widening the county is going to do.”