KEY POINTS:
Part of Auckland's Southern Motorway was closed for more than five hours last night after a truck-and-trailer unit rolled on to its roof, causing misery for commuters.
The driver was taken to Middlemore Hospital in a serious condition after the accident about 7pm just after the Mt Wellington turn-off.
Inspector Willie Taylor, of the police northern communications centre, said the truck, travelling north, rolled on to its roof and the trailer unit swung away from the cab into a barrier and some trees.
The wreckage covered three northbound lanes.
Mr Taylor said traffic was initially backed up about 2km to Princes St in Otahuhu.
It was diverted down the Mt Wellington turn-off, across the Mt Wellington Highway and back on to the Southern Motorway.
It took until about 11pm for heavy haulage equipment to arrive and begin to move the truck and trailer. The road was due to open early today.
The cause of the crash was not known late last night. No other vehicles were involved.
A spokesman for the Fire Service said staff attended the crash but did not have to cut the driver from the cab.
