Three drivers were also not wearing a seatbelt.
More than 700 drivers were fined for using their phones illegally in the Western Bay last year, the most recent police data available. The fines totalled $58,000.
Inspector Brent Crowe, the Bay of Plenty roading policing manager, said cellphone use while driving had become a "major concern" for police.
"From our observations, people flouting the ban is pretty much widespread. We will continue to take a zero-tolerance approach to those who do so, as it not only puts themselves at risk but other road users."
Crowe said distractions featured prominently in recent crashes in the Bay of Plenty region.
"We need every road user to be solely focused on driving their vehicle, and to put their cellphones away," he said.
Joint Road Safety Committee chairwoman Margaret Murray-Benge said she despaired when she saw people talking on their phones, particularly with children in their car.
"I see it all the time and there is absolutely no excuse for this risky illegal behaviour."
AA's Bay of Plenty district council member Terry Molloy said he would like to see police take away the license of anyone caught texting and to make the person walk home.
Molloy said he would personally also like to see the infringement amount increased.
Caroline Perry, director road safety advocacy charity Brake New Zealand, said she was disappointed but "not surprised" by the numbers caught flouting the ban.
"Some people are so addicted to their cellphone they have to use it 24/7," she said.
Perry urged people to ensure their cellphone was well out of reach so they were not tempted to use it.
Nationally 58,000 were pinged for using their cellphone while driving last year.
Mobile phone offences in the Western Bay police district:
2014: 367
2015: 638
2016: 717
2017: 702
2018: 736
Source: NZ Police