Drivers get the message about low speed tolerance level for December-January period.
All speed cameras across the country have been recalibrated with the new 4km/h speed tolerance as part of the police push to reduce summer road deaths.
The summer push began on Sunday and police assistant commissioner of road policing Dave Cliff said drivers appeared to be paying attention.
The 12 fixed cameras around the country and 44 mobile cameras were manually calibrated to the 4km/h threshold by technicians for the start of the December 1-January 31 campaign, he said.
It was too early to analyse the first day's data, but anecdotally, he said, the lower threshold had already caught at least one dangerous driver.
"In Auckland, near the harbour bridge, we stopped a driver that was travelling at 89km/h in a 80km/h zone. The driver was stopped and breath tested and found to be over the limit. It was their third drink-driving charge. So they had their licence suspended and their vehicle impounded.
"That was a really good indicator first off that drivers are ignoring the speed limit ... we will breath test you and if you are drink-driving, we will catch you."
However, the early word from traffic cops nationally was that most drivers were obeying the limit, he said.
To give the campaign further publicity, $350,000 of ACC money has also been pumped into a summer advertising campaign.
Radio adverts on national and regional airwaves kicked off on Sunday, Mr Cliff said, while billboards would begin popping up on major roads throughout the country in the next 7 to 10 days.
The signs feature roadside police officers with messages promoting lines such as, "Summer speeding will be stopped", "Anything over the limit is speeding", and, "The summer of no speed tolerance".
The December-January period traditionally has a higher road toll than other times of the year.
Last summer there were 346 crashes causing 57 fatalities.