A truck and trailer unit carrying containers has rolled at a major Northland roundabout.

Whangārei police Senior Sergeant Steve Dickson said the roll over happened just before 9.30am today at the Port Marsden Highway roundabout near Ruakaka on SH1.

The driver escaped with minor injuries and was treated by St John Ambulance staff at the scene.

Traffic was continuing to flow but police asked drivers to take care at the roundabout as they worked with others to right the vehicle.