The widening of Ga. 400 between the exits for McFarland Parkway and Ga. 369/Browns Bridge Road in Forsyth County will begin Monday, weather-permitting.
The project covering 13.4 miles will cost $47.4 million and is scheduled to be completed by May 31, 2018. It will eventually add one lane in each direction on Ga. 400.
The Georgia Department of Transportation said Wednesday in a news release that the work will also include repairs of the damaged concrete driving surface of existing Ga. 400 lanes.
All lane closures will be overnight or on weekends, according to the DOT. Weekday overnight work in northbound lanes will be from 9 p.m. to noon of the next day, with weekday overnight work in southbound lanes running from 7 p.m. to 5 a.m. of the next day.
Weekend work in northbound lanes will go from 9 p.m. Fridays to noon Mondays, with weekend work in southbound lanes running from 7 p.m. Fridays to 5 a.m. Mondays.
Damaged sections of the road will be replaced with new concrete, the DOT said, this fall. The agency said construction will begin adding an additional lane in each direction in the spring.
Bridges over Big Creek and the Sawnee Creek portion of Lake Lanier will be widened as part of the project, according to the DOT.
The Georgia DOT has contributed $13 million for the work. The Forsyth County Transportation Bond, passed with 63-percent approval by Forsyth voters in November 2014, will fund the remainder of the project.
A ceremonial groundbreaking was held Wednesday.