MONTGOMERY COUNTY, Va. -

3:30 p.m. Update:

The Virginia Department of Transportation reports that the accident has been cleared.

There are still major delays in the area.

Drivers are still urged to use caution when driving through the area.

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A tractor trailer accident is causing some major backups on Interstate 81 in Montgomery County.

It's in the southbound lane, around mile marker 121.

Traffic is at a stand-still right now, and there's a backup 7 miles long.

Drivers are urged to avoid the area and expect delays.