Two fire appliances and a support vehicle from Ruakaka helped control traffic. SH1 was closed for about 15 minutes as police Serious Crash Unit officers carried out preliminary investigations.
Highway patrol Sergeant Chris Goodall said both the cyclist and the 4WD had been heading north.
The cyclist was knocked off his bicycle and landed in a ditch by the roadside while the 4WD rolled before coming to a rest on its wheels.
Mr Goodall said police would not release the identity of the dead man until his next of kin were notified.
Ruakaka Volunteer Fire Brigade station officer Jeff D'Ath said the woman and her children got out of their vehicle and were sitting on the side of the road when emergency service personnel arrived.
Seatbelts had helped prevent injury to the woman and children.
"It could have been worse without the seatbelts, considering the vehicle was in a 100km/h zone," Mr D'Ath said.
The woman and children were treated for cuts and bruises before being transferred to Whangarei Hospital by St John Ambulance paramedics.
No charges had been laid late yesterday.
Mr D'Ath said a group of cyclists heading south had stopped after the incident and offered help before continuing with their journey.
The crash happened about half an hour after a motorcyclist was seriously injured in a crash in Lower Hutt.
