'Terrifying': Container falls off back of truck on Auckland motorway

The incident was reported to police around 12.45am this morning. Photo / Supplied

One person has been injured after a container fell off the back of truck on Auckland's Southern Motorway in wet and dark conditions early this morning.

All motorway lanes except one near Penrose were blocked after a truck carrying the container was involved in the crash around 12.45am.

An Auckland man driving home at the time described the "terrifying" moment he saw the container lying across the lane ahead of him as he rushed to brake.

"I was so lucky that I stopped my car because I was going 100km (per hour) as well."

The man, who the Herald agreed not to name, said he was about 40-50 metres away from the container before he saw it.

He said with rainy, windy and dark conditions, "it was very hard to see from a distance that something was wrong."

Another car had driven into the container, he said, but the driver appeared to be okay.

"It was horrifying. I'm just glad this guy was fine."

The man said drivers of three or four cars parked their vehicles several metres ahead of the crash with their hazard lights on to warn other motorists. Emergency services were at the scene within five minutes, he said.

A police spokesperson said the truck driver sustained moderate injuries and temporary road closures were put in place at the time.

"Police assisted with an incident on the Southern Motorway where lanes became blocked by a container.

"The incident occurred after the truck carrying the container became involved in a crash. ...all but one of the southbound lanes were blocked near Penrose."