Inspector Al Stewart said the main highways would be much busier as people begin journeys to holiday destinations or to see friends and family.
Read more: Revealed: Holiday danger spots and times
"If you're travelling on our highways you should be seeing marked patrol cars," he said.Intersections were a focus for road policing staff, he said.
The average fatalities at intersections in the last five years was 3.6, but last year there were 12 people killed at intersections.
"We're well above the average... so we're having a big focus there, especially intersections at major arterial routes and highways," Mr Stewart said.
People travelling north to holiday destinations like Hanmer, Nelson and Blenheim need to take their time on the state highways, Mr Stewart said.
"They're good roads, but they're only as good as the drivers on them."
Many motorists will be taking long journeys and need to take breaks from being behind the wheel, Mr Stewart said.
Police would be focusing on drivers over the alcohol limit.
"We encourage everyone to plan how they are going to get home before they leave for a party. Book a taxi early or nominate a sober driver in the group who can take you home at the end of your celebrations," Mr Stewart said.
"We'd love to see a significant drop in crashes over all including the serious injuries and fatalities.
"We'd like to go out there and catch no one offending, I don't think that's going to happen, but that would be really nice."
As at December 24, there have been 287 deaths on the roads. This time last year there had been 247 deaths, 40 less than this year.
The official holiday road period starts at 4pm today and runs until 6am on Monday, January 5.
Last year's Christmas-New Year road toll was seven, from a total of 193 reported injury crashes. But the official holiday period was three days shorter than this year.
The deaths of four people yesterday in a crash near Waipu were not included in the official Christmas-New Year road toll.