Police are concerned drivers are getting complacent about using mobile phones after the number caught using them has doubled since 2010.
More than 60,000 motorists have been pinged since the ban in mobile phones came into effect in 2009 - almost half of them in Auckland.
Last year 15,440 had been caught using cellphones while driving by the end of September - almost double the 2010 tally with three months still to go.
In 2010, just over 8200 people were caught using their phones while driving. Fines now total more than $1 million a year and almost $5 million has been collected since the end of 2009.
Police Assistant Commissioner Dave Cliff said only one survey had been done of cellphone use so it was difficult to say whether the increase was due to less compliance or stricter enforcement.