Day of carnage on Auckland's roads

One of the cars involved in a six-vehicle pile-up on Auckland's Southern Motorway. Photo / Paul Estcourt

A collision between two trucks and four cars caused chaos on the Southern Motorway in Auckland last night, blocking three lanes and leaving hundreds of motorists in a traffic jam.

Two people were taken to Auckland City Hospital after the smash just after 7.30pm near the Tecoma St motorway offramp, in Ellerslie.

The woman driving a 4WD vehicle - the third car in the pile-up - said the crash happened because drivers were trying to avoid a motorway maintenance vehicle.

"It came out of nowhere and there was no warning," she told the Herald.

"Cars started skidding, trying to avoid one another. Just slamming on the brakes."

The truck driver and the woman driver of another car were both taken to Auckland City Hospital with moderate injuries.

The accident was cleared within 45 minutes, but it caused chaos on the motorway with traffic being backed-up from Greenlane to the Ellerslie offramp.

It was the second major crash in Auckland yesterday after a woman was taken to Auckland City Hospital with serious injuries when her car and a bus collided.

Emergency services were called to the accident in Withers Rd in Glen Eden, West Auckland, shortly before 2pm.

The woman, in her 30s, was trapped for about half an hour.

Police cordoned off surrounding roads while firefighters cut off the car's roof to get the woman out. She was taken to hospital in a serious condition but was the only person hurt.

Police spoke to the bus driver and up to 10 passengers. At the scene, the dark grey station wagon was a mangled mess with the front of the car and driver's door crumpled.

The airbag on the driver's side had popped out and bits of the car body and shattered glass lay strewn over the road and footpath.

The bus suffered only minor damage to the driver's-side front corner.

Police said the woman's vehicle crossed the centre line and hit the oncoming bus.

Acting Sergeant Colin Nuttall, of the Waitemata serious crash unit, said it was too early to say whether speed was a factor.

"Obviously the bus is much larger than the car and so the car's going to have more damage than it."

Given the relative sizes of the vehicles, the car would not necessarily have had to be travellingat speed to be damaged so badly.

A resident on the street said she was inside her house when she heard a "loud bang outside".

The woman, who did not want to be named, said cars were regularly speeding down the street.

"[Authorities] should be doing something about it. They need to put restrictions on this road because day and night people just zoom downhere.

"I'm too scared to even walk across [the road] to the shops because they just come past that corner so fast."