A car that caught fire on State Highway 1 today may have suffered a mechanical fault, police say.
Heavy traffic has eased following the incident north of the Harbour Bridge today, New Zealand Transport Association Auckland says.
Motorist Richard Morse was driving past the car when it "almost exploded" in flames.
He could see a police car and a man standing further along the motorway but it was hard to make things out because of the smoke, Mr Morse said.
"We couldn't see it for a while...there was a little bit of smoke and I thought 'That could be a car fire' and as we got closer it got more, and then we came round the corner it was fully alight and a kind of fireball came up.
