A truck has rolled on the Pacific Highway north of Newcastle, causing major delays.

The B-double lost control and crashed at Coolongolook just before 5am on Tuesday.

The incident shut down southbound lanes for some time, but a contra flow is now in place.

COOLONGOLOOK: A stop/slow traffic control is being set up past the site of this truck crash on the Pacific Hwy near Melaleuca Dr. At the moment, there is only 1 northbound lane open. All southbound lanes and 1 northbound lane closed. pic.twitter.com/I9NNtl2x00

— Live Traffic NSW (@LiveTrafficNSW) June 10, 2019

Intermittent stoppages will take place during the vehicle-salvage operation, which is expected to take some time.

For the latest traffic information, visit www.livetraffic.com

The stop/slow is now in place on the northbound side of the road. Expect delays, allow extra time and follow the directions of traffic controllers. https://t.co/y2sDKon5nL

— Live Traffic NSW (@LiveTrafficNSW) June 10, 2019