Construction of a flyover connecting U.S. 278 to Bluffton Parkway is still several weeks away, but Beaufort County officials say they've already created a plan to keep traffic flowing.
The plan largely consists of keeping two lanes open in both directions during daytime hours, when traffic volumes are highest, according to Rob McFee, county director of infrastructure and engineering.
"There will be no daytime lane closures on 278. It will be similar to the roadway work and bridge work going on now," he said, referring to the widening of U.S. 278 from McGarvey's Corner to Simmonsville Road in greater Bluffton.
These and other constraints are not optional. The contractor must agree to the traffic plan.
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The flyover will start at Bluffton Parkway's intersection with Buckingham Plantation Drive and extend over the marsh between The Gatherings and Buckingham Landing. Ramps will connect either side of U.S. 278 leading to the foot of the Karl S. Bowers Bridge to Hilton Head Island.
Anywhere from 50,000 to 64,000 vehicles cross that bridge each day, depending on the month and day of the week, and blocking one or more lanes during peak travel times can back up traffic for miles.
"Construction is already cumbersome enough having extra equipment and materials and cones" in the road, said Jared Fralix, assistant resident construction engineer for the S.C. Department of Transportation. "If we were going to get out there in a lane and shut down traffic, it would be a serious headache on everybody."
Six contractors submitted bids, and the county is waiting for state and federal highway agencies to review the proposals, McFee said. After that is completed, the low-bidder can be certified, and the contract can go to County Council for final approval.
"The apparent low bid came in at about 7 percent above the engineers' ($34.3 million) estimate," he said. "Considering the complexity of this project, this is in line with our expectations."
Based on those projections, the county is conducting a "financial review" to make sure there is sufficient funding. McFee said he believes the project is "still on track."
"I have to be sure there isn't a problem. If there is a problem, now is the time to know," he said.
About $15 million in state and federal money has been secured for the flyover. Additional money came from the county's 1-percent sales tax, which expired recently, and from impact fees charged on new development.
The county has learned what works and what doesn't during several recent road projects and has developed its plan accordingly, McFee said.
"The key with any significant project is that you develop as good a plan as you can when you offer it out to the contracting community for a bid," he said. "But you must also remain supple and flexible depending on the conditions that prevail day to day."
Follow reporter Casey Conley at twitter.com/EyeOnBeaufortCo.