The holiday road toll has risen to five after two fatal crashes this afternoon, while a serious multiple vehicle crash stalled holiday traffic through Warkworth, north of Auckland.

At around 1.30pm this afternoon, a 16-year-old boy died instantly after a ute he was travelling on the back of rolled on Rakau Road, 47km north east of Taupo near Reporoa.

The ute was being driven by a 15-year-old and another youth was also riding on the back.

The 16-year-old was pinned beneath the vehicle and died of his injuries and the second passenger was flown to Waikato Hospital with back and spinal injuries.

The driver, a 15-year-old local youth, was not injured, acting Senior Sergeant Andrew Lynch of Rotorua's Strategic Traffic Unit said.

A 38-year-old male motorcyclist has died after a crash between a car and a motorcycle on Kaiwhaiki Rd, a gravel road just off State Highway 4 near Whanganui, just before 2pm this afternoon.

Police said the vehicles were travelling in opposite directions on an unsealed section of a narrow rural road.

The four occupants of the car were uninjured.

Meanwhile, two seriously injured motorists were taken to hospital after three cars collided at the intersection of Kaipara Flats Rd and State Highway 1 near Warkworth at 3pm, a police spokesman said.

Fire Service Northern Communications shift manager Jaron Phillips said one person was cut by fire service staff from a vehicle at the scene.

State Highway 1 was closed near Warkworth since the incident and diversions were put in place, he said.

The official holiday road toll period started at 4pm on Christmas Eve and runs until 6am on January 5. Last year, 13 people died on the roads during the period.

The first victim of the holiday period was Gayle Jean Anderson, 44, who died in a crash near Dunedin on Christmas Eve.

Just minutes into Christmas Day, a 40-year-old man died in a hit-and-run in south Auckland. Vineshwar Singh was hit by a car on Helvetia Road, Pukekohe, and died a short time later. The car immediately left the scene.

Mary-Lee Huata, 17, died after the Toyota Hilux she was travelling in was in a collision on Putere Road, 7km west of Raupunga, 38km south of Wairoa yesterday. The Toyota was being driven by a 13-year-old boy.

One person remains in a critical condition, three are in a serious condition, four are stable and four have been discharged after the pileup on State Highway 2, 35km southwest of Hastings, about 5.15pm on Monday.

In light of the rising toll, Superintendent Paula Rose, national manager road policing, urged everone to think carefully while on the roads.

"The choices we make can be life or death ones - so let's think about ourselves and other people," she said.

"Two of the fatal crashes so far this holiday season have involved the tragic loss of young lives and this hits us all in the community."