Police are investigating whether another vehicle was involved in the crash which flipped a rubbish truck, killing its driver.
The driver of the rubbish truck that rolled several times on Auckland's Southwestern Motorway on Monday night was yesterday named as Rawhiti Hita, who was 70 last month.
He lost control of his truck about 4.20pm on Monday and rolled several times, spreading debris over north- and south-bound lanes between the Dominion Rd on-ramp and Hillsborough Rd off-ramp.
The crash delayed rush-hour motorway traffic in both directions.
It is understood Mr Hita was thrown from the Green Gorilla truck's cab. He died at the scene.
A Waitemata serious crash unit spokeswoman said it would be "at least several weeks before any definitive cause" of the accident was known.
Senior Constable Karl Bevin yesterday said police were investigating whether another vehicle might have been involved before the crash, but it was too early to know for certain what had caused the accident.
"We're following up on a couple of inquiries," he said.
"We're still in the process of obtaining the motorway camera footage."
Other checks that had to be completed included whether the rubbish truck might have been overloaded, whether a tyre may have blown, or whether Mr Hita had a medical episode before the crash.