Motorists be warned - drivers speeding over the Christmas holidays and beyond will be caught.
Until the end of January the speed limit threshold has been reduced to a tolerance of 4km/h.
The move coincides with police trialling 28 new high-visibility red and orange marked cars - which will be rolled out across the country.
Assistant Commissioner Road Policing Dave Cliff said police would be targeting speed and high risk behaviour on the roads.
They will also continue focusing on seat belts, child restraints and drink driving.
He said it was the first time the reduced speed limit had been introduced beyond a long weekend.
"The decision to introduce the reduced tolerance in combination with a range of other high profile initiatives is about saving lives and preventing lifelong injuries to those Kiwis who will be taking to the roads this summer."
Research in the past five years showed there was a greater reduction in speed-related deaths and injuries during holiday periods when police had enforced the reduced threshold as part of its approach, compared to non-holiday periods, Mr Cliff said.
During all holiday periods in 2008, before police implemented the reduced speed threshold, there were 48 speed-related fatal or serious injury crashes. But in 2012, when police operated a reduced threshold in holiday periods, speed-related fatal and serious injury crashes dropped to just 16, he said.
"That's a decrease of 67 per cent," he said.
Police will be maintaining a highly visible presence throughout the summer, with a strong focus on removing speeding, drunk, drugged and high risk drivers from the roads.
"Everyone, not just police, has a part to play in making sure we all enjoy a safe summer on our streets, roads and highways. Road safety is everyone's responsibility."
If you wish to report a driving incident call *555 from your cellphone.