The southbound lanes of Auckland's northern motorway were expected to re-open by 4.30pm, hours after a a single vehicle crash left one person seriously injured.
The lanes were closed following the crash near Oteha Valley Road at around 12.50pm.
One person with serious injuries was trapped in the vehicle and emergency services were at the scene for some time.
Traffic was congested north and south of the harbour bridge.
Police have thanked motorists for their patience while the lanes were closed.