They all went through to hospital with ambulance.
This year's toll is currently on par with last year and police say they are "cautiously optimistic" there'll be fewer deaths this festive season.
National road policing manager Superintendent Steve Greally said he was pleased the toll wasn't any worse than the 2014/15 period but said: "one life was even too many".
Mr Greally said fatal crashes were particularly heartbreaking this time of year.
"They've had their loved ones on Christmas Day and then they're lost."
He told drivers to expect delays on the roads as people left the main centres for their summer holidays and urged drivers to take extra caution on the roads.
"We hate to see people make stupid decisions for being frustrated."
Holidaymakers hit the roads and traffic hit peak levels today on routes out of Auckland.
The Northern Gateway toll road and the Thames turnoff from State Highway 1 at the southern base of the Bombay Hills were bumper-to-bumper at midday. And CCTV cameras showed queues both at that intersection and from the Hibiscus Coast Highway to State Highway 1, where ramp signals held up campervans and other vehicles waiting to join northbound traffic emerging from the toll road's Johnstones Hill tunnel.
The Transport Agency warned drivers of "significant delays" at the Thames turnoff.
The agency predicts heavy flows from Auckland to Northland, the Waikato and Bay of Plenty again tomorrow.
It advises holidaymakers to avoid the heaviest periods, such as from 10am to 1pm on both the Puhoi-Wellsford section of State Highway 1 and eastbound along State Highway 2 through Maramarua to the Coromandel Peninsula and Tauranga.
Those heading south to Hamilton and beyond should avoid peak travel from 10.30am to 12.30pm.
Traffic is likely -- based on a Transport Agency's study of previous summer holiday travel patterns -- to be heavy between Paeroa and Tauranga via the Karangahake Gorge for much of tomorrow, but particularly over the four hours from 11am.
Congestion is expected to continue on the main road north from Auckland every day this week, and in the opposite direction from Friday until about 6.30pm on Monday, the final public holiday of the Christmas-New Year period.
The Transport Agency is repeating its standard advice to holidaymakers -- who will include those heading for the three-day Northern Bass festival near Mangawhai from Tuesday until New Year's Eve -- to consider the alternative route from Auckland along State Highway 16 via Helensville.
Westbound traffic heading back to Auckland through Maramarua after New Year's Day is likely to be heavy during most daylight hours from about 11am on Saturday until the following Tuesday evening, even after many offices reopen from the holidays.
Solid traffic flows are predicted every day for the next week on the South Island's most popular holiday run, from Cromwell to Queenstown via tate Highway H6, and in the opposite direction from New Year's Day until late on Monday.
Police attended two separate crashes on SH1 about 7km south of Oakleigh early this afternoon, each involving a car in collision with a truck and only about 1km apart. Two injured occupants of a car reported to police as having crossed the highway's centre line at its intersection with Cotton Rd were taken to Whangarei Base Hospital by ambulance.
But nobody was reported hurt in the second collision, further south, between a car and a petrol tanker.
The police reported traffic flowing past both crash sites.
