The lane is expected to be closed until 9 a.m., according to VDOT.
Traffic could be moving slowly on Interstate 81 in Montgomery County right now.
A lane headed south is closed near where the Interstate and Friendship Road cross.
It's because of the truck climbing lane project in that area.
Workers hope to have the lane open in about half an hour or so.
WDBJ7 will keep you updated both here and on the air.