Two serious crashes in upper North Island

File photo / NZPA

A motorcyclist is in a critical condition after his bike collided with a truck on the Brenderwyn Hills south of Whangarei this evening.

Emergency services were called to the crash on State Highway 1 about 5pm, an ambulance spokeswoman said.

The motorcyclist was removed from under the truck and was in a critical condition.

Westpac Rescue Helicopter was on the way to the scene.

Meanwhile, a logging truck crashed on State Highway One just outside Warkworth causing 9km traffic jams this afternoon.

Senior Sergeant Lance Gardiner from police northern communications said the truck hit a power pole about 2.35pm.

There were no injuries but the incident brought down power lines and caused a 9km tailback for northbound traffic.

"All we know is it has taken out a power line, and live power lines were over the road. It's lost a few logs off its' trailer as well.''

Vector had cut power to the lines around the crash area, he said.

Ambulance communications team leader Ngaire Jones said the driver walked away unharmed.