A fatal truck crash has closed the M1 Pacific Motorway in both directions at Mount Kuring-gai.

A B-double rolled and caught fire about 2.30am, near the Church Street overpass, burning a load of wool it was transporting.

The body of the driver was found inside the truck.

Traffic is heavy and motorists are being told to avoid the area, with no forecast for when the highway will reopen.

One southbound lane and one northbound lane is now reopened.

Transport for NSW Greater Sydney Chief Operations Officer Howard Collins tells Ray Hadley the debris is being cleared.

“There’s at least an hour and a half delay.

“This afternoon may be impacted, we are trying our best to clear the site but there’s a lot of stuff.”

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