Overnight lane closures will start Tuesday and are slated to last about three weeks as the Georgia Department of Transportation extends a westbound left-turn lane on Dawsonville Highway/Ga. 53 at Green Hill Circle. Single-lane closures in both directions between Shallowford Road and Green Hill Circle will begin at 7 p.m. Tuesday, running from 7 p.m. to 6 a.m. daily, including weekends. The 170-foot extension of the turn lane is now scheduled for a May 3 completion, weather-permitting.