Experts are taking aim at police plans to target speeding drivers during summer, saying the campaign will hit "mums and dads" but miss those who cause most fatal crashes.
Police will have a reduced tolerance of 4kmh above the official speed limit during this month and next.
During that period last year there were 416 serious injuries on New Zealand roads, including 57 deaths.
Road safety campaigner Clive Matthew-Wilson said the campaign was aimed at "happy holiday families".
However, research had shown fatal crashes were far more often caused by substance abusers, tired drivers, highly reckless drivers, the very young and the very old.
"All five of these groups are largely immune to road safety messages because they believe they're already doing OK."
About 80 per cent of fatalities occurred at speeds below the legal limit, Mr Matthew-Wilson said.
Massey University marketing lecturer Dr Terry Macpherson said the Government had overstated the role that advertising played in lowering the road toll.
"Ads telling people not to do something generally only work if the person watching the ad is already on your side.
"An example is anti-drug campaigns for teenagers, which have been running for decades.
"On paper, they make perfect sense. In the real world, most studies show they make little or no difference at all."
Criminologist Greg Newbold said he said he was cynical about the police campaign.
He gave the example of a gang associate who caused the deaths of four people when he crashed while drunk and on cannabis on New Year's Eve 2001.
"I'd like to know how ticketing mothers for going 5kmh over the speed limit can prevent accidents like this."
Police have said that previous reductions in the speeding tolerance had led to a 67 per cent reduction in road crashes.
During Easter last year, there were no road deaths, which was the lowest figure since records began in 1956. Fairfax NZ
- Taranaki Daily News
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