A witness described a fiery scene when he arrived about 10 minutes later.
"The car was fully going for it. It was well involved in fire. It was just smoke everywhere."
Fire crews were working to put out the flames, which had also spread into nearby bush, he said.
Section of Triangle Rd closed
As a result of the crash, a section of Triangle Rd - between Zefiro Drive and Lincoln Park Ave - has been closed until further notice, as the Serious Crash Unit investigates the circumstances of the crash.
An Auckland Transport alert was issued on Twitter at 6am telling motorists to expect the section of road to "remain closed for some time this morning" due to a police investigation.
People were told to allow for extra travel time or to use an alternative route.
A northern fire communications spokesman referred all other inquiries to police.
The witness said he saw a man sitting on the opposite side of the vehicle. One of the doors was wide open, he said.
The crash comes just over three months after another fatal crash on the same stretch of road.
Friends Jack Heritage and Viliami Muru-Teutau, both 20, died in a crash on the morning of Boxing Day.
Emergency services were called to the Triangle Rd bridge - near Lincoln Rd - just before 6am that day. Police confirmed the fatalities later that morning.
