The Georgia Dept. of Transportation is trying to keep Interstate 75, one of the busiest highways in the state, in good condition without severely impacting commuters.
Last summer, Archer Western won a three-year $81.3 million contract to mill, inlay and pave the 8.9-mi. (14.3 km) stretch between Barrett Parkway and Glade Road. The project is scheduled for completion on April 30, 2009. The federal government will pay for 90 percent of the repairs, with the state picking up the rest of the tab.
The contract does not allow lane closures during rush hour.
“We face damage penalties of $10,000 per hour every hour that we don’t have traffic open to full capacity on weekday mornings,” said Robert Bird of Archer Western.
That’s good news for commuters. The bad news, according to Bird, is that slowdowns will occur on the weekends.
“The majority of the work — impacts, single lane closures — will indeed be around the clock through the weekend. There will also be windows of work on most weeknights in the overnight hours,” he said.
Archer Western began excavating and paving the shoulders of I-75 in late March. A Volvo G930 motorgrader was used to finegrade the subgrade after a subcontractor, Pavement Products and Services, milled the 27-in. (69 cm) section. This process provided a quick turnaround and smooth product on which the contractor constructed the new section.
The new stone base will be placed with a Blaw-Knox RW195D road widener. Archer Western plans to use a Terex CMI SF2204 variable width paver, Gomaco 6300 paver, Gomaco RTP500 belt placer and a Gomaco PS2600 placer-spreader to perform the concrete paving. Slipform paving is the most efficient way to place new concrete roadways, Bird said, especially in conditions such as this project where time is a factor and roadways must be opened before morning rush hour.
The inside and outside shoulders will be a full depth replacement. New stone and an asphalt base will be set underneath 12 in. (30.5 cm) of concrete pavement. In the travel lanes, 12 in. of asphalt will be milled out and replaced with concrete pavement.
Concrete pavement was chosen because of its durability.
“A value engineering study and life cycle cost analysis were both done during the design phase of the project,” said Mohamed M. Arafa, GDOT spokesman.
“It was determined that if the Georgia DOT opted for asphalt paving, the asphalt would have to be replaced every 8 to 10 years. If the department took the concrete paving route in repairing this almost always busy section of I-75, the life cycle would be almost four times that of asphalt paving.”
Armed with this information, the department opted for concrete pavement, even though the short-term price tag was a little higher.
The project’s original construction plan called for double lane closures and the use of a contra-flow traffic pattern. This would have severely hindered traffic flow, but this was deleted by the Federal Highway Administration.
“The double lane closures and contra-flow traffic have been eliminated,” Bird said. “We’ve successfully proven to the state that we can do this work utilizing only single lane closures at both a cost savings, and reduction in traffic impacts.”
But there’s a disadvantage for the construction workers.
“By eliminating double lane closures, it’s made our work tougher logistically with less space to work in,” Bird explained.
Still, Archer Western is glad to do the work with minimal impact to commuters.
The state is confident that the project will benefit commuters in the long run.
“Nationwide studies confirm that highway investments pay for themselves when measured in terms of industry productivity benefits,” Arafa said. “This portion of the interstate carries between 183,970 and 229,650 vehicles per day. It needed to be repaired.” CEG
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