Truckers are finding shock absorbers torn from trailers and steering joints failing more often and blame the worsening state of highways.
By some measures the country's highways are deteriorating, prompting a call from driver lobbyists for the Government to urgently tap into COVID-19 funds.
Bone-weary John Hickman of Taranaki is backing the billion-dollar call to make highways better.
"Maintenance bills [are] going through the roof year on year," the veteran operator said.
His business, JD Hickman, keeps 85 trucks on the road but when he recently stumbled over a bundle of tie-rod ends, which can wear out due to constant use on bumpy roads, in the workshop, he thought, "Hell, I didn't realise how bad it was getting".
"It's just the roughness of the ride - the potholes, the digouts," Hickman said. "You create a judder bar at every repair if you like.
"Just affects all the steering joints, tears the shock absorbers off our trailers - you've got to see it to believe it.
"And of course the customers' goods in the back get a good milkshake ... so it's not good for them either."
Regular services keep his trucks on the highway safely but can do nothing to address the aching backs he and his drivers have at the end of a week.
"You know at the end of the week, you've done a week's work, that's for sure.
"State Highway 3 is a shocker, from Waverley north to New Plymouth it's just terrible, Third World stuff.
"Some of the bridge abutments you drive over those and it's just an horrendous bang as you go through it."
The Transport Agency defends its record, saying it has been exceeding its performance targets for road conditions.
It did a record amount of maintenance last year and had left no money earmarked for maintenance since 2018 unspent, it said, adding, however, that an expanding road network and more traffic mean there must be trade-offs, plus storms have hit roads hard recently.
The agency had improved its way of contracting out repairs seven years ago and this ensured "that the right work is done in the right place, and at the right time".
It told the Office of the Auditor General (OAG) that before this change to Network Outcomes Contracts, it was in fact over-investing "by renewing state highways too early".
The OAG concluded both that the agency's spending was "well targeted", but that it also had undershot the rate of highway depreciation for a decade.
The Road Transport Forum representing truckers prefers to point to other figures. Its own survey shows a 55 percent rise in truckers' maintenance costs nationwide in five years while a national pavement survey by NZTA showed road rutting worsening in that time by up to a third and the rate of seal failure doubling.
The forum has joined five other lobby groups to demand a realignment of pandemic road spending.
"Instead of putting money into so-called shovel ready projects when they're not shovel-ready in the sense that they're not going to be able to start until they consented, until there's a labour force in place to deliver them, which could be years, that actually fixing the dilapidated condition of New Zealand roads on some major state highways around the country would be a really good investment," forum spokesperson Nick Leggett said.
The AA has also signed a letter to the transport and finance ministers calling for catch-up funding.
"We have seen an increase in allocated funds in the last couple of years," AA spokesperson Mike Noon said.
"But it doesn't offset the huge underinvestment over the past decade.
"And what this means is that our road network condition is actually deteriorating. And if we don't act and do more soon, then the actual final bill to fix these roads will be a lot more and the roads will become a lot less safe than they are today."
The condition of roads ranked as the second most vexing problem for drivers in AA surveys, he said.
Their solution is to outlay $300 million in each of the next three years, on top of the more than $500m current maintenance spend.
Transport Minister Phil Twyford said the Government agreed there had been underinvestment for a decade prior to 2017 so had increased highway maintenance spending on average by 36 percent.
If re-elected, it would up that another 17 percent, he said.
"Our record investments in rail will help take pressure off our roads by moving more freight to rail. It's going to take more than a few years to undo a decade of neglect," Twyford said.
The Government has put $600m to cover COVID-19 impacts on the National Land Transport Fund this year.
The Transport Agency is responding to high crash rates on some highways, such as SH5 Napier to Taupō and SH6 from Nelson to Blenheim, by moving to reduce the speed limit, not address the design or maintenance.
Another lobbyist, Clive Matthew-Wilson, argued that trying to cut speed was misguided, when studies show fitting median barriers and roadside fencing could cut death and serious injury by 90 percent.
The focus on new "luxury" roads was also wrongheaded, he said.
"One tiny section - the Pūhoi to Warkworth highway ... is going to cost upwards of $878 million," he said in a press release.
"For $878 million, the Government could have already installed median barriers, roadside fencing and roundabouts on all or most of the 160km of highway between Auckland and Whangārei."
The Office of the Auditor-General (OAG) noted that some people it spoke to, including staff from the agency, suppliers, councils, and road user groups, said they believed parts of the network were getting worse, or about to get worse.
"Spending less [than depreciation] indicates some risk to the agency's long-term ability to maintain the condition of state highways," the OAG said.
"The agency is aware of this risk, and has highlighted that additional investment in the network will be required as part of developing the next Government Policy Statement on Land Transport."
The agency's general manager of transport services, Brett Gliddon, said a finite budget meant continuously making trade-offs.
A Road Transport Forum analysis of NZTA figures, highlighted the "unparalleled increases" in heavy vehicles on the roads.
Since 2010, the maximum truck size has increased from 44 tonnes to about 63 tonnes under special permits.
"The level of adoption by commercial heavy vehicle owners exceeded forecasts rendering initial predictions of impact as obsolete," the analysis said.
Most of the truck growth had been since 2014, which the analysis said was illustrated by the number of heavy vehicle kilometres travelled rising from 1.6 billion to 2.5b in 2020, a 56 percent increase.
It noted from the national highway pavement (surface and road foundation) survey:
Average seal life remaining reduced by half due to heavy use and limited maintenance, or "sweating the asset"
Four out of five measures of roughness and rutting have got worse by, on average, 14 percent
A more than doubling to almost 5 percent of the percentage pavement that requires treatment due to low levels of skid resistance
John Hickman, from up in his truck cab on the highway from Auckland back home, questions if roads are being built properly to begin with.
"The new highways - the Wellington one, the Waikato Expressway - we've just come up that this morning and there's potholes, digouts, repairs already and this is a new highway.
"It's not built to the heavier standard. The left-hand lane is rough as guts where the heavy traffic travels, the right-hand lane is not as bad - that tells me there's not enough substructure when they build them."
It was time Government ministers got into a truck cab to experience it for themselves, Hickman said.