More than 16,000 people have illegally driven through the Links Ave bus lane, according to the Tauranga City Council.
Four weeks into the trial, 8000 infringement notices have been issued, the council said in a statement.
The council's director of transport Brendan Bisley said the council needed "to see behaviour change".
"The main purpose of the trial is to look at ways of getting the current levels of traffic down to a safer, more reasonable level for a residential street.
"Parents need to be able to send their children off to school knowing they have a street to use that is safe to ride or walk on. Safety remains the key issue."
Bisley said the number of infringements was a reminder to everybody to be vigilant while driving.
"Driving towards Links Avenue from any direction, drivers will pass between three to five signs about the trial. If you don't notice them, safety is clearly an issue," said Bisley.
Some 8500 warning letters were sent to drivers who drove through the bus lane in the first two weeks of the trial.
Council said the letter explained that the bus lane had been used and that future infringement would mean the standard $150 bus lane fine would apply.
Team leader of regulation monitoring Stuart Goodman said 8000 infringement notices were issued to drivers who have used the bus lane illegally.
"At least 25 per cent of those are to drivers who have used the lane before and have received a warning letter or previous infringement.
"We'd like to see more compliance as the trial progresses. The goal of the bus lane, and the subsequent infringement notices, is to stop drivers using Links Avenue as a through road."