State Highway 6 has re-opened near Owen River, north of Murchison, after two trucks lost control in icy conditions yesterday afternoon.
The road was closed for several hours after a log truck rolled and a second truck jack-knifed, spilling logs across the highway.
The driver of the log truck was initially trapped in the cab and was airlifted to hospital by the Nelson Marlborough Rescue Helicopter.
The helicopter's flight crew said the truck and trailer unit rolled after failing to negotiate icy roads. A second truck narrowly avoided colliding with it after it had rolled.
A team from Nelson Fire Service was flown to the site with specialist cutting equipment to help free the trapped driver.
The rescue helicopter's intensive care paramedic treated the driver for spinal injuries and he was flown to Nelson Hospital for further treatment. He is in a stable condition.