"Once again we expect people will drive to holiday hotspots throughout New Zealand. The key is to think about the other people you share the road with.
"Longer journeys on unfamiliar roads can be enjoyable, but arriving safely depends on driving socially and following the road safety basics."
Mr Griffiths said driving at a safe speed was crucial because, regardless of the cause of any crash, it was speed that determined survival.
"Mistakes will happen on the road but a lower speed and a safe following distance gives you the ability to react to somebody else's mistake," he said.
Mr Griffiths said December and January were statistically some of the riskiest months of the year.
"Speed-related crashes increase typically increase, which is why police will be enforcing the speed limits nationwide.
"Police will continue to enforce new alcohol limits for drivers over 20. If you plan to drink at all, our advice is to arrange another way to get home.
"Fatigue can also be a factor, so drivers should ensure they are well rested, take regular break and share the driving if they can.
"Police will be highly visible on the roads this summer, doing our best to ensure we all get to where we are going safely. We will be doing our bit, enforcing safe limits - the rest is up to the drivers."
Police said today's fatal crash occurred on State Highway 1 at Tirau Rd near Karapiro this afternoon.
A man was found dead at the scene, while an 8-year-old boy from Tokoroa suffered critical head and abdominal injuries.
The boy was taken to Waikato Hospital by the Hamilton-based Westpac Rescue Helicopter.
At least three other people suffered moderate to serious injuries and were taken to hospital by ambulance.
Waikato Hospital said the injured boy was in a critical condition in its intensive care unit.
The boy's 45-year-old mother and 11-year-old brother were both being assessed in the emergency department. A 25-year-old Hamilton man and a 16-year-old girl from Te Awamutu were both stable.
It is understood the injured were travelling in two of the vehicles, which were badly damaged.
A woman and children were believed to have been travelling in one of the cars heading south. The man killed was thought be travelling alone and heading north.
One of the cars involved in the crash was towing a boat and was seen detached from the vehicle and in a hedge.
Earlier, a woman was seriously injured when she was hit by a car on Wharf Rd in Coromandel township this morning.
The woman, aged in her early 20s, was taken to Waikato Hospital with serious injuries.
The weekend got off to a bad start yesterday when six people were injured in a two-car crash on State Highway 2 at the Athenree Gorge between Katikati and Waihi.
Five ambulances and two helicopters were needed to transport all the injured, including one child to Starship Hospital.
Four people suffered serious injuries and two people were in a moderate condition.
Another person was also seriously injured yesterday, when three cars became involved in an accident, leaving one of the cars on fire.
Emergency services were called to the scene of a serious crash on State Highway 1 at Dome Valley, between Warkworth and Wellsford, and were able to pull all the occupants of the cars.
- Additional reporting: New Zealand Herald
