Motorists now are traveling along two southbound lanes and one northbound lane.
The transition to four lanes will begin about Aug. 27 as the Georgia Department of Transportation opens a second northbound lane while closing one of the southbound lanes for final work, said Mark McKinnon, DOT spokesman.
"They have to have a place to put the equipment as they work through there," he added.
All four lanes are supposed to open about two weeks later.
The $25 million project, which involves a nearly 7.5-mile stretch of road, is set for formal completion on Dec. 31.
Typically, contractors try to open new roads "as soon as they get the lanes ready, but there’s a lot of things that have to happen afterward," McKinnon said.
"There’s guardrail work. Most contracts include (planting grass), and they’ll have to do some grading ... along the shoulders."
The "punch list" may require correction of certain work done along the new road, McKinnon said.
The busy thoroughfare is a major route carrying traffic from Interstate 985’s Exit 16, where a $75 million reconstruction is taking place, through part of Jackson County to Interstate 85.
Businesses, churches and homes dot either side of the road, including a new Kroger-anchored shopping center, commercial development across from the retail center and a recently opened Ingles grocery store.
The Hall County school system’s World Language Academy, which is housed in the old Chestnut Mountain Elementary School, also sits on the road.
In its 2030 Long Range Transportation Plan, the Gainesville-Hall Metropolitan Planning Organization has projected that Winder Highway would be widened from Ga. 211, or Tanners Mill Road, to I-85 between 2014 and 2020.
The Winder Highway widening feeds into the Exit 16 reworking, which involves the construction of a new I-985 interchange at Atlanta Highway, the widening of Ga. 53, or Mundy Mill Road, and new lanes on Atlanta Highway.
Work has finished on some portions of the project, as motorists in the heavy-traffic area likely have noticed.
Atlanta Highway now features two left-turn lanes onto Mundy Mill Road, near Blackshear Place Church and Chick-fil-A.
And Atlanta Highway motorists crossing Ga. 53 and heading toward the planned interchange now have an extra lane in which to travel.
That segment of Atlanta Highway passes by Poplar Springs Road, which carries traffic to Johnson High School and South Hall Middle School. It also runs by the Hall County Library System’s Blackshear Place branch and the Hall school system’s bus depot.
The road also features a new traffic light at Robert Wood Johnson Drive.
Motorists heading from the I-985 interchange now can’t turn left onto a road supporting the bus shop, library and a county-run compactor site. Motorists need to travel to Robert Wood Johnson Drive, turn left and then turn left on a road that connects to the sites.
Barbara Perry, branch manager of Blackshear library, said patrons can pick up maps at the front desk showing how to get to the branch.
"It’s a little bit confusing for people, but hopefully they will learn they can use the back road with the light," she said.
And she feels confident they will, adding, "People are fairly determined if they are going to use the library."