Motorists using the Waterview Tunnel have forked out over $2.5 million in speeding fines over just eight months.
Police operate four speed cameras in the tunnel area, with one at each entrance and exit to the tunnel.
Figures released to the Herald under the Official Information Act show 29,047 speed-camera notices were issued to drivers between July 4 2017 and March 7 2018.
The total value was $2,579,490.
The notices included 19 summonable offences, which did not contribute to the monetary figure.
The figures also do not include speeding tickets issued by officers.
The infringement rate has fallen since the first six weeks after the tunnel opened, when motorists were issued $948,220 in speeding tickets.
However, NZ Police national road policing manager Superintendent Steve Greally said the number of tickets issued illustrate that people are continuing to speed.
"[They] are therefore putting themselves and others at risk. This is always of concern."
Speed was globally recognised as the lead contributor to crashes and how serious they were.
"Consequently, any driver travelling over the set speed limit can expect to be ticketed," Greally said.
"Police's aim is to prevent death and injury on our roads. Police would be very happy never to issue another infringement notice because it would show that people were driving in a safe manner which would reduce the number of people harmed on our roads."
Motorists have previously raised concerns about the speed levels in the tunnel.
One woman, hairdresser Tess Coote, was fined $360 for speeding during two round trips to visit her sick father in Waikato Hospital.
"It's a money-making tube," the Kingsland resident told the Herald last year, saying she was conscious of the 80km/h speed limit driving through the $1.4 billion tunnel.
Coote received four speeding tickets in the mailbox for driving through the tunnel both ways on September 2 and September 3. She was clocked at speeds of between 92km/h and 98km/h.
Three of the fines are for $80 and one for $120 for allegedly driving at 98km/h.
Police do not retain any of the money from fines on drivers exceeding the safe posted speed limit. All of this goes to the Government's consolidated fund.
In September, the NZ Transport Agency agreed to restore the speed limit on the motorway surrounding the Waterview tunnel to 100km/h, after a petition attracted more than 4000 signatures.
NZTA is proposing to raise the variable speed limit around the tunnel from 80km/h to 100km/h, but not for the approaches or inside the tunnel.
A spokesman said it was to help manage the higher risks associated with an enclosed tunnel environment.