PULASKI COUNTY, Va. – UPDATE
This crash has been cleared and traffic is flowing smoothly.
Drivers should avoid heading south on Interstate 81, if they can.
A mile south of the Route 100 Hillsville exit, at mile marker 88, traffic is backed up in Pulaski County because of a tractor-trailer crash.
As of 10:01 p.m., VDOT is reporting that traffic backups are about two miles.
At one point all southbound lanes were closed and traffic was backed up about five miles.