Nearly $1 million worth of speeding tickets were issued to Auckland motorists using the Waterview Tunnel in just six weeks.
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 shows 9756 speeding infringement notices were issued to drivers between July 21 - the day the cameras went live - and August 31.
The total value of the notices generated by speed cameras operating in the Waterview Tunnel was $948,220.
Police noted the amount recorded on each notice did not necessarily indicate the amount paid.
National manager of road policing Superintendent Steve Greally said the data showed a large number of drivers were simply going too fast.
"The speed limit set for Waterview Tunnel is there to keep all road users safe and a crash would likely cause significant harm and traffic disruption," he said.
"Success to police would be issuing no infringements."
Safe speed cameras on average reduced fatal and serious injury crashes by
about 20 per cent within the sphere of influence of the camera - up to about 1km, Greally said.
"We know from international evidence that safe speed cameras do have an
impact on slowing people down.
"That is why these safe speed cameras are operating, alongside other road safety measures, to encourage people to reduce their mean speeds and ultimately reduce deaths and injuries."
Of the 1,520,767 vehicle trips taken in the tunnel during the July 21 - August 31 time period, 6 in 1000, or .6 per cent, attracted a speeding fine.
One woman, hairdresser Tess Coote, was fined $360 for speeding during two round trips to visit her sick father in Waikato Hospital in July.
"It's a money-making tube," the Kingsland resident told the Herald earlier this year, saying she was conscious of the 80km/h speed limit driving through the new $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 fines associated with drivers exceeding the safe posted
speed limit. All of this goes to the government's consolidated fund.
NZTA agreed last month to restore the speed limit on the motorway surrounding the Waterview tunnel to 100km/h after a petition attracted more than 4000 signatures.
Brett Gliddon, NZTA system design manager, said the process of installing the infrastructure needed to extend the variable speed limit on sections of State Highways 16 and 20 around the Waterview Tunnel was under way.
A legal process which needed to be completed before the variable speed could be increased to 100km/h was also under way, Gliddon said.
Speed limits inside the tunnel would remain at 80km/h to manage the higher risks associated with an enclosed tunnel environment.
"The NZ Transport Agency encourages safe speeds to reduce incidents and help keep all road users safe.
"The impact and consequences of an incident inside a tunnel can be more significant which is why it's important people follow the sign posted speed limit."
Automobile Association spokesman Barney Irvine said the question on everyone's lips would be whether the tunnel was being used for revenue raising.
"My answer is no, it's not. The police aren't trying to trick anyone here; there's plenty of signage in the approach to the tunnel of the speed limit and the fact cameras are operating," he said.
"When you see a figure like $1 million it seems really high, [but] they're talking about infringement rates of .6 per cent."
Comparing the tunnel to Wellington's Ngauranga Gorge, which had infringement rates of .3 per cent, Irvine said it was likely people were getting caught out because the road was new and drivers were still getting used to the area.
"What this really highlights for us is the need for speed camera sites to be reviewed every six or 12 months not just in Waterview but right around the country," he said.
If too many speeding tickets were being issued at any one spot, more needed to be done in terms of providing signage and changing the road environment to reduce speed.
In terms of revenue raisers, last year Auckland Transport (AT) issued nearly 60,000 infringement notices for out of date car registration.
Of those, 58 were issued to one vehicle received in the year to November 2016.
At $200 a pop, the 58,174 notices were valued at $11,634,800 half of which AT was entitled to.
However, the authority pointed out the amount paid was likely less than the face value of the tickets.
An official information request received by Fairfax showed police handed out close to 124,000 tickets for out of date registration nationally last year.
All the money collected went to the government.