Eighteen trucking companies are being investigated after a police crackdown uncovered mass safety breaches on the highway north of Auckland late last year.
However, three Auckland operators said that cowboy firms had been getting away with it around the city's highways and roads for years.
The roadside checks on hundreds of trucks clearing containers from Northport at Whangārei last December revealed almost one in five was a safety threat.
Now the Transport Agency Waka Kotahi is looking further into 18 companies, based between the central North Island and Northland, caught with multiple faults.
The companies have not yet been named, but NZTA said it would name them and revoke their operating licences if they did not comply.
"We are looking at the systems that each of these operators has in place to ensure their fleets are maintained safely and that driver fatigue is well managed. We're reviewing what they have done since the [Northland] operation to rectify the problems found, and monitoring the steps they will take to operate safe and compliant fleets going forward," Waka Kotahi safer commercial transport senior manager Brett Aldridge said in a statement.
Regulators have been criticised in recent years for not investigating upstream supply-side problems that undermine road safety.
However, several major operators claim the Auckland police could have caught these same operators much earlier, but they had been slack about trucks within the city limits.
"These people have been doing it around Auckland for however long and aren't getting policed to the same degree," Lance Peach, who runs 42 trucks at Super Freight in Wiri, said.
Container trucks were the worst, with some so dirty drivers could not see if anything was wrong during their required daily safety "walk-around" a rig, Peach said.
"I'm not satisfied with it.
"We're paying to put our tyres on, or carting the correct weights.
"It's pretty disheartening when you see someone else is blatantly disregarding the rules."
He said he had witnessed safety breaches of apprehended truckies while doing the Northport run himself in December.
"Running bald tyres and overloading, yes, it certainly is [dangerous] particularly on running a route like that" with windy sections in Dome Valley and on the Brynderwyns."
A second operator claimed some container trucks went for "months and months" without proper checks, in between their six-monthly compulsory Certificate of Fitness checks.
There were "a lot of trucks on the road a bit below standard on mechanical grounds".
In Auckland, police weren't picking many of them up, this operator said.
A third operator, Calven Bonney, who is high up in the Road Carriers Association, agreed the errant Northport-run truckers "could have between caught a lot earlier" if police had the resources to put into it.
The industry word was they lacked staff, and certainly, those experienced enough to do truck inspections as part of the Commercial Vehicle Safety Team (CVST, formerly the CVIU), Bonney said.
Road Transport Forum chief executive Nick Leggett said having 80 to 90 specialised CVST officers nationwide was not enough.
The CVST experienced a big drop-off in roadside inspections in the three years to 2018.
All three operators mentioned that Auckland's key Stanley Street truck-checking station by the port appeared to have been staffed a lot less in the last three or four years.
"I don't know why," Peach said.
"But there's plenty of other places where they could be popping up and looking at them as well", which was not happening either, he said.
"That's why they've found problems with certain trucks up there.
"And they should have found those around Auckland before they started running up and down to Whangārei."
Police have been approached for comment.
NZTA 'will not hesitate' to revoke licences of non-compliant operators
Aldridge said the Northport enforcement operation ranged from immediately rectifying relatively minor problems (such as with mudguards or reflector lights) "through to ordering vehicles with serious safety issues off the road".
"Where we find safety deficiencies in the way a Transport Service Licence holder operates, Waka Kotahi will work with the operator until those deficiencies are rectified.
"Ideally, the operators are willing to be guided and educated towards compliance but ... [we] will not hesitate to remove licences from operators who do not take the action required to comply and ensure safety for both their drivers and for other road users," he said.
Leggett said NZTA should name the 18 companies.
"I have asked them [to]. I'd be very interested to know who the operators are" and if they were forum members.
The road safety regime "only works well with good regulation from government because if certain operators are cutting corners they enjoy a competitive advantage," Leggett said.
Bonney expressed wariness about the NZTA investigation, and the Northport police operation.
It had cost a "shocking" amount, flying in a lot of CVST officers, who stopped drivers often multiple times a day, and "made our industry look bad when they were trying to save our clients and save the country".
Because of congestion at Ports of Auckland related to the pandemic, 1200 shipping containers had been offloaded at North Port.
Some mechanical faults, in general, could be put down to poor roads shaking loose electrical fittings, Bonney said, while adding he did not know the details of the Northport stops.
Also, industry experience was that the CVST had officers who lacked the experience to properly inspect big trucks, he said.
The small percentage of cowboys did not represent the industry, he said.
Bonney, like Leggett, wants to know who the 18 are so the association could approach them to offer help.
"I've been sitting in trucks since I was 18 months old and the conversation every morning tea, lunch and dinner is exactly what we are having today," the septuagenarian said.