The Automobile Association says it's too soon to tell if reduced speed tolerance make roads any safer.
The official holiday period ended last Friday morning with seven deaths, but another three people have since died in serious crashes.
AA motoring affairs general manager Mike Noon said lowering the speed tolerance to 4km over the limit instead of 10 has had a calming effect on traffic.
But, he said, other factors come into play, including driver fatigue and not wearing seatbelts.
Mr Noon said he will wait to see the figures for deaths, injuries and crashes for the period of the tighter speed rules, which runs until the end of this month.