Dramatic images reveal aftermath of two-truck crash on Auckland's Southern Motorway

Images have emerged of a two-truck crash that blocked all northbound lanes on State Highway 1 at Pokeno on Auckland's Southern Motorway for a time this afternoon.

The Auckland Rescue Helicopter Trust says the driver of the truck and trailer that rolled suffered multiple injuries and was in a critical condition.

It was decided to take him to Middlemore Hospital by road as this was the faster option, a spokesperson said.

According to NTZA, one northbound lane is now open to traffic.

Emergency services at Pokeno truck crash. Source: Supplied

However, the Pokeno off-ramp is closed due to a separate crash.

NZTA are warning motorists to expect delays in the area.

Pokeno truck crash. Source: Supplied