Major vehicle inspection company VTNZ has broken road safety rules by using an inferior brake test on Waiheke Island for months, and the Transport Agency let it.

Photo: VTNZ

A manager who oversaw the testing says the rate of detecting brake problems on the island's trucks and buses dropped dramatically, and it wasn't safe.

An estimated 600 brake tests on Waiheke, for heavy vehicle Certificates of Fitness, many of them on school and tour buses and trucks, used the old decelerometer method.

RNZ got a tip-off about this shortly after the government hauled the Transport Agency over the coals last week for failing to enforce vehicle safety rules for years.

Vehicle Testing New Zealand (VTNZ) then admitted using the inferior test, saying its roller brake machine broke in March 2017.

The agency's Brake Protocol stipulates decelerometer testing should be used for only up to two days; VTNZ used it for 18 months, until August this year.

The Transport Agency knew about this but the delays persisted.

Paul Greenwood was a VTNZ manager at Warkworth who helped oversee Waiheke.

"After it became very apparent that the preferred option was just using a decelerometer, and no roller brake machine would be fitted, I informed my manager and area manager that not reinstalling the roller brake machine was going against what was stipulated in the Certificate of Fitness, and Entry Certification Brake Test Protocol and Procedure," he told RNZ by email.

Waiheke example of VTNZ 'doing wrong and carrying on regardless'

VTNZ Waiheke has been put on the list of 850 vehicle safety operations or authorised inspectors and certifiers, now being scrutinised by Auckland law firm Meredith Connell, which last week took over the Transport Agency's lead road safety responsibilities.

"This whole incident was just an example of VTNZ just doing wrong and carrying on regardless," Mr Greenwood said.

He began to collect figures to show how the old brake test was performing on Waiheke. He sent these to both VTNZ and the Transport Agency, he said.

"Out of 130 inspections carried out after the roller brake machine had been removed, there were 30 fails and three of those were due to brake problems.

"Out of 92 inspections carried out before the roller brake machine was removed ... there were 41 fails [and] 17 of these were brake issues ... 15 of the 17 were due to brake balance problems which would not have been picked up on a decelerometer."

According to this, the roller machine picked up six times more brake problems than the old decelerometer test, and 90 percent of the faults found would be invisible to the old test.

A decelerometer test is done by driving a vehicle at 30km/h then braking and must be done on a flat, sealed road. It measures the stopping distance but cannot detect if one wheel is braking worse than the other; unbalanced brakes can lead to a vehicle veering suddenly under sharp braking.

Mr Greenwood, who left VTNZ after the conflict over Waiheke, said he heard from testing officers that local people expressed worries about use of the old test.

A tour bus company told RNZ the revelations the old test had been used for so long were of concern.

'We believe there is no public safety issue' - VTNZ

Fullers360 runs the public buses on Waiheke. "All our Waiheke Bus Company vehicles have gone through COF testing at the required time and are compliant," chief executive Mike Horne said.

VTNZ told RNZ it had not broken any brake test rules.

Its acting national operations manager Gavin McNaught described Waiheke as a Grade 4 test site which was allowed to use a decelerometer in this way.

"We believe there is no public safety issue. We don't believe there's been any compromise," Mr McNaught said.

The Transport Agency, however, said it did break the rules; Waiheke had been upgraded to a Grade 3 site, which cannot use the old test for more than two days.

"The alternative testing method did not comply with the requirements of a grade 3 site," an agency statement said.

After VTNZ became aware the agency had told RNZ this, Mr McNaught then said he had relied on old information about what Grade the Waiheke site was, and apologised "for any confusion".

It did not believe "any immediate safety risks" were posed. RNZ asked the agency to provide the evidence it has to back this assertion, but it has not done this; nor has it commented on the brake test figures Paul Greenwood gave it.

VTNZ concedes it used old test at Waiheke for too long

Decelerometers were still used at some remote test sites, the agency pointed out.

Mr Greenwood said on one occasion VTNZ had told him it was exempt from the Brake Protocol entirely, even though all testing stations of heavy vehicles must abide by this.

In a 20-minute interview with RNZ, VTNZ's Gavin McNaught repeatedly defended using the old test for so long.

Asked if the agency approved this, he said, "I haven't got records to that effect but they did know we were using a decelerometer, yes ... our understanding was that we were allowed to use it."

However, he then said the Transport Agency had upped the ante last October.

"No, it wasn't OK with them and we were under pressure to get the brake machine up and running as soon as we could. They had been chasing us up, inquiring about when we would be returning to using the roller brake machine."

It still took another 10 months for proper brake testing to resume.

Mr Greenwood said VTNZ told him several times it had an exemption from the Brake Protocol, and had the OK in an email from the Transport Agency, but would not show the email to him "as VTNZ did not want it to get out into public domain".

"If indeed they did believe they had an exemption ... surely when this is questioned by a respected staff member you would look into it further and then provide a fact-based explanation with supporting back up. Nothing was offered."

Asked if it was VTNZ policy to use a decelerometer for longer than two days, Mr McNaught said no, and that none of the company's 77 other inspection sites would do that, because this test was less effective.

Customers were not told

Mr McNaught eventually conceded Waiheke used it for too long - and that they should have been more upfront with local customers.

"If they're there with their truck, their car, their bus, [they] would witness what was happening. [But] in hindsight we possibly should have highlighted for every single customer who came through ... we should have."

He was not aware of anyone returning after a test to complain about their brakes, he said.

Mr Greenwood said he has heard some locals got a retest on the new roller machine, "for peace of mind".

The only reason he said he was ever given by VTNZ for the delays was that installing a new machine was not cost effective.

Mr McNaught said cost did not come into it; the 18-month delay was due to "issues" installing a new machine.

Such machines are easy to source and cost less than $100,000.

RNZ has asked VTNZ repeatedly if the decelerometer testing itself was done properly, as there does not appear to be much room to do the tests at the Waiheke site, which is inside Fuller360's bus yard, while the road outside is on a slope. RNZ has not received an answer.

VTNZ has not addressed the drop-off in the number of brake faults being found by the decelerometer, which Mr Greenwood said he reported to it.