Tractor-trailer crash caused delays on Interstate 81

A look at the backup at mile marker 140 at 6:45 p.m. (Copyright by WSLS - All rights reserved)

ROANOKE COUNTY (WSLS 10) - A tractor-trailer crash in the northbound lanes of Interstate 81 caused a major backup on Thursday night.

At 6:49 p.m., the north right lane was closed at mile marker 145.8 in Roanoke County and traffic backups were estimated at about 6 miles, according to the Virginia Department of Transportation.