Currently, traffic is affected in both directions.

About 4am, two semi trailers were travelling north on the New England Highway when the vehicle at the rear drove into the back of the semi in front at around 80km/h.

Investigations are still continuing into the cause of the collision.

However, the driver of the rear semi trailer was driving on a suspended licence.

“A number of critical fatigue breaches were identified in his work diary,” a Hunter Valley Police District spokesperson said.

“His work diary was confiscated and he will be charged at a later date.

“One driver suffered minor injuries and both heavy vehicle combinations were extensively damaged and towed from the scene.”

Emergency services, Roads and Maritime Services (RMS) personnel and HAZMAT crews are working at the scene to clear the busy stretch of road.

Alternating stop/slow traffic conditions will be in place to allow motorists to pass in one direction at a time.

Delays are expected, according to www.livetraffic.com