Another person has been killed during what the Automobile Association (AA) says is one of the busiest times on the road New Zealand has had.
The police said they understood a motorcycle rider who was in a group with other motorbikes hit a fence this afternoon at Te Poi, south-east of Matamata in Waikato.
St John said it sent three vehicles and a helicopter to the scene shortly after 1.30pm.
There have been more than 370 crashes around the country since Christmas Eve.
Three other people have been killed in two separate crashes - one person died on Christmas Day in a crash near Whangarei, while two people were killed in a head-on crash south of Tokoroa on Boxing Day.
AA spokesman Dylan Thomsen said the roads had not been this busy for several years.
"That's because the fuel prices are very low at the moment, and we've also got more international visitors than New Zealand's ever had before ... and large numbers of them [are] out on the roads."
Hundreds of those international visitors had completed the AA's new online programme, which was aimed at educating tourists about New Zealand's road rules and driving conditions, Mr Thomsen said.
The police had not previously provided the total number of crashes, so it was hard to say if there had been more overall crashes this year compared to previous years, he said.
Many of the crashes occurred in the usual hotspots - between Auckland and Northland, Auckland and the Coromandel, and on the Kapiti Coast north of Wellington.
Traffic today has eased north of Auckland and Wellington after earlier hold-ups in the usual hotspots.
In an update about 5pm, the New Zealand Transport Agency warned there was still a queue of traffic northbound on State Highway 2 just before Paeroa, as holiday-makers head to the Coromandel Peninsula.