A string of crashes on Auckland's roads caused severe congestion yesterday as thousands flocked to events in the city - and worse is feared today as Pasifika, the Arts Festival and the Blues match combine to create the perfect traffic storm.

Thousands of families will be leaving the Pasifika Festival, at Western Springs, as fans arrive at Eden Park for this afternoon's Super Rugby game against the Bulls.

Yesterday, families travelling to Pasifika faced delays when a car towing a trailer slammed into the median barrier on the Northwestern Motorway at Waterview about 1.30pm, scattering bricks across the road and closing all but one lane.

Earlier, traffic was reduced to a crawl between Pokeno and Drury when a motorbike and a 4WD collided about 9.30am, leaving one person with serious injuries.


A police spokesman said a truck also jack-knifed on Mangere Bridge about 3pm, causing traffic to back up for 2km to Queenstown Rd.

Some commuters travelling to the Kumeu Show on the North Shore also faced heavy traffic due to a scrub fire which forced the evacuation of the Westfield Albany mall. Two 14-year-old girls were being spoken to about the blaze.

New Zealand Transport Agency spokesman Ewart Barnsley said the city's highways were "heavily congested" yesterday, but not nearly to the same degree as on Thursday when a crash on the Newmarket Viaduct caused the worst traffic gridlock in years.