The North Carolina Department of Transportation will close the southbound lanes on Highway 421 near exit 286B in Wilkesboro overnight Friday to begin repairing the collapsed area of the roadway. The exit ramp off 421 onto 268 washed away Tuesday night and into Wednesday morning due to the heavy rain. The section will be closed from 8:00 Friday night until 8:00 Saturday morning. DOT says one lane will be reopened after 8:00 a.m. on Saturday. The DOT has a detour route set up with signs to take drivers around the closure during the overnight hours.