Multiple crashes has seen a section of State Highway 1 in Waikato closed.
The affected part of the highway is from Mercer to Te Kauwhata, with all southbound lanes closed and northbound down to one lane.
Police say the initial crash between a car and truck happened about 4.30am.
Waka Kotahi NZ Transport Agency advises southbound traffic will be detoured at Mercer via Koheroa Road onto State Highway 2 where they will travel east until meeting Okaeria Road. They will then need to follow Okaeria Road through Waerenga and Te Kauwhata, before rejoining SH1.
The detour route is likely to add at least 30 minutes to journey times.
Northbound traffic should plan for long delays or consider an alternative route.
NZTA says it is expecting the clean-up would take "some time".
There is also heavy fog in the area and visibility is poor, so motorists are asked to take extra care.
Lane closures are likely to remain closed for some time for clean-up and vehicle recovery and motorists should delay their travel, where possible, or to make use of detour or alternative routes, NZTA says.
SHARE ME