A person is critically injured after a crash on Auckland's Southern Motorway, with the collision causing traffic mayhem on Thursday afternoon.
Waka Kotahi has urged motorists to avoid Papakura and Takaanini areas due to "significant congestion".
Due to the complexity of the crash, all northbound lanes on State Highway 1 will remain closed for "the next few hours", the transport agency said.
People are advised to detour along Great South Rd through Papakura and Drury.
"Please delay any travel in the area if you can, otherwise expect lengthy delays," Waka Kotahi said.
One person is in a critical condition after the crash, a police spokesperson told Newshub earlier.
Hāto Hone St John said the crash involved a van, truck and car.
Two ambulances, three rapid response vehicles and an operations manager attended the scene.
The serious crash unit is investigating, police said.
