ROCKBRIDGE COUNTY, Va. (WDBJ) - Traffic is backed up on I-81 in Rockbridge County Thursday evening.
A big rig crash at mile marker 181 led to the closure of all northbound lanes, according to VDOT .
The southbound left shoulder and left lane were also closed as of 8 p.m.
No information has yet been released about any injuries or the cause of the crash.