State Highway 1 has been blocked north of Kaitāia after a milk delivery truck rolled, while people have died in crashes near Russell, and in Buller District.
The crash at Waipapakauri, 15km north of Kaitāia happened about 12.40am on Friday, and the driver was moderately injured, police said.
The northbound lane was blocked and a large volume of milk spilled across the highway.
Traffic was being diverted around the crash scene but delays were likely.
Police, St John Ambulance and the Kaitāia Fire Brigade were working at the scene, with volunteer firefighters tasked with washing down the highway.
A heavy haulage tow truck had been dispatched from Kaitāia to remove the milk truck.
Holiday road toll creeps higher, with fatalities in Buller and Russell
The summer holiday road toll reached double-digits early on Friday.
Police said one person died after a single-vehicle crash overnight on State Highway 69 at Inangahua, in the Buller District. Motorists were asked to avoid the area.
And one person died at the scene of a single-vehicle crash near Russell, where another person from the crash remained in a serious condition.
Police said the collision happened shortly after 11.30am on Friday, and Russell Whakapara Road was closed between Waikare Road and De Nora Drive. Drivers were asked to avoid the area.