Four people have died so far in a bad start to the summer road toll, including three motorcyclists.
The three motorcyclists died in two separate crashes on Saturday, and there was a death and serious injuries at other crashes in the North Island.
Two people were killed in a crash involving a van and four motorbikes, during a charity ride in Taranaki.
Earlier in the day, a farmer, 21, riding a motorcycle died in a head-on collision with a car near Opotoki.
And another man was been killed and three other people injured in a three-car-crash near Ruakaka, 30km south of Whangarei.
Police say the three vehicles in that crash collided just north of the Prescott Road and State Highway 1 roundabout, about 4pm on Saturday.
One survivor has critical injuries and two others have moderate injuries.
Police Superintendent Carey Griffiths said a lack of awareness by drivers is often a factor in crashes where motorcyclists are killed.
At the Taranaki crash, State Highway 3 just outside Normanby was blocked from about midday and traffic diverted until 5pm.
Police say five people were been taken to hospital, two with serious injuries.
A spokesperson for the Bikers' Rights Organisation says at least one of those killed was a rider taking part in the Round the Mountain Charity Toy Run.
Bikers' Rights president Murray Heal says the crash scene was a mess.
"There was just a pile of scrap metal which used to be motorbikes," he says.
The crash happened about an hour and a half into the event.
"I went back to the Salvation Army in Hawera where we were having lunch, gathered everybody around, and asked them what their opinion was, and they decided to continue out of respect," Mr Heal says.
The police serious crash unit is investigating.
Police are also working out what happened in a two-car collision near Wellsford in which six people - including two children - were injured.
That crash happened shortly after midday, forcing the closure of State Highway 1 at Te Hana for much of the afternoon.
The ambulance service says two people were critically injured, and the rest suffered serious or moderate injuries.