Watch: Massive traffic jam as truck jack-knifes, blocking all northbound lanes on major Auckland motorway

A truck has rolled this afternoon on Auckland's Southern Motorway, blocking the northbound lanes just after Papakura.

The New Zealand Transport Authority posted a tweet about the incident at 2:30pm, warning motorists to avoid the area.

The picture accompanying the tweet shows a large truck and trailer partly on its side blocking both lanes of the motorway on the northbound side shortly after Papakura.

Video sent to 1 NEWS by Kurt Schultz, who is currently stuff in traffic near the incident, shows a long line of cars waiting for the truck to be cleared, with people getting out of their vehicles while they wait.

Mr Schultz says a tow truck is now on the scene and he hopes it will be cleared shortly.