SALEM, Va. (WDBJ7) -- UPDATE
The North exit ramp at MM 137 is now open to traffic on I-81N.
Crews have just cleared a tractor trailer fire at that exit.
No injuries have been reported.
Crews are working towards cleaning up the scene where a tractor trailer caught fire on I-81N at MM 137.
Officials say the driver noticed the brakes were smoking and pulled off at the exit.
When the driver pulled over, he realized that the contents inside the tractor trailer were burning.
WDBJ7 was told that the tractor trailer was transporting materials used for plastic bottles and jugs.
Salem and Roanoke County crews have the fire under control at this time, but say clean-up will last at the North exit until 8 a.m.
Crews are at the scene of a tractor trailer fire on I-81 northbound.
VDOT says drivers should expect delays at mile marker 137.
The north exit ramp is closed at this time.
Check back with WDBJ7 for more traffic updates.