A car has flipped onto its roof on State Highway 1 in central Auckland and skidded across the tarmac, leaving two people injured.
The NZ Transport Agency said the crash, which occurred around 9.15am, was initially blocking two right lanes southbound just before Fanshawe St on the Northern Motorway in St Mary's Bay.
Delays were back to Esmonde Rd on the North Shore and could affect those heading into the central city for the Queen St Santa Parade from 1pm.
A witness at the scene said two people were injured in the crash and were being cared for by St John Ambulance staff.
A police spokeswoman said one person was moderately injured and another had minor injuries.
By 11am, the NZTA said congestion was beginning to ease.
Meanwhile, emergency services are also at the scene of a single motorcycle crash on the Princes St, Otahuhu, off-ramp, southbound, on the Southern Motorway.
Police had attempted to stop the bike, which then fled and crashed shortly after.
The motorcyclist is reported to have moderate injuries.
The road will be closed for some time while the Serious Crash Unit examines the scene, and diversions are in place.
Motorists should avoid the area and take an alternative route if possible, a police spokeswoman said.