Nearly third of New Zealand's entire roading network past its estimated lifespan

The seal on nearly a third of New Zealand's entire roading network is past its estimated lifespan, Newshub can reveal.

Waka Kotahi NZ Transport Agency says that doesn't necessarily mean the roads need resealing. Some roads can pass their expected design life and not be degraded to a point where renewal is justified, it says.

The National Party, however, believes Kiwis will be concerned by the revelation and wants Waka Kotahi to be more focused on road maintenance. 

But the Transport Minister says the Government has increased road maintenance funding after it flatlined under the previous National Government. 

Official information from Waka Kotahi shows 32 percent of roading surface area is overdue for renewal. That is based primarily on the design life given to the surface at the time of construction or the intended lifespan expected based on traffic volume and mix. 

The transport agency stresses a road's design life is just an estimate. It also doesn't mean it will start crumbling once it's surpassed. 

Neil Walker, Waka Kotahi's national manager of maintenance and operations, told Newshub roads aren't automatically resealed when they reach the end of their estimated lifespan. The agency also doesn't wait until a road has reached that point to reseal it if work is needed earlier, he said. 

Instead, Walker said Waka Kotahi undertakes regular inspections and maintenance processes to ensure "age-related faults" are recorded and repaired, keeping the network "safe and accessible". 

"There may be several valid reasons why a road has not been resealed at the end of its design life," Walker told Newshub.

"Some sections of road will pass their expected design life and not need resealing, as the seal is still performing adequately and has not degraded to a point where it justifies a renewal. This can be the case with state highways which carry low traffic volumes, especially those with lower volumes of freight."

On the flipside, some roads may need to be resealed before the end of their expected lifespan, Walker said. 

National wants the Government more focused on road maintenance.
National wants the Government more focused on road maintenance. Photo credit: Getty Images.

National's transport spokesperson Simeon Brown said most New Zealanders "will be concerned" to learn about a third of the network is past its estimated lifespan. 

The Pakuranga MP said the Government should be "investing into our roading network which is what people pay user charges and petrol taxes for" rather than focusing on other projects like light rail. 

He also took aim at proposals to lower speed limits across much of the roading network.  

"It is clear NZTA is taking the easy option of reducing the speed limits instead of investing into the roading networking and increasing safety through better-maintained roads," Brown told Newshub.

"NZTA should get on with keeping our roads up to stand instead of trying to slow Kiwis down with blanket speed limit reductions."

But Walker said a backlog of renewals was created as a result of actions in the mid-2010s - which was when National was last in office. 

"The volume of state highway renewal work did decrease in the mid-2010s, in line with a flatlining of available funding for road maintenance, and this has created a backlog of renewals that we continue to work through with the additional funding received for this purpose in the 2021-24 National Land Transport Programme (NLTP)."

Michael Wood, the Transport Minister who has previously labelled National "outrageous hypocrites" for complaining about the state of the roads, is again throwing the blame National's way.

"For eight years, the National Party froze road maintenance funding and we now have a massive backlog of work to get back on top of that and make sure we have a resilient network," he said.

"The party that raided state highway maintenance funding was the National Party… they used that to fund their Roads of National Significance."

He said no National Land Transport Funds are currently going to light rail. The current phase has been funded through separate Crown appropriation. 

Nearly third of New Zealand's entire roading network past its estimated lifespan
Photo credit: NZTA

The above graph highlights an increase in total expenditure on state highway maintenance in recent years. In the 2021-24 NLTP, $2.8 billion was allocated to state highway maintenance, an increase of 30 percent on the 2018-21 NLTP.

Brown said the Government confuses "outcomes with spending". 

Walker said Waka Kotahi currently has its largest-ever programme of spring and summer renewals planned, with more than 2400 lane kilometres of resealing or rebuilding to occur between September 2022 and April 2023. That's about 10 percent of the network. 

"We’re committed to improving the overall condition of our state highway network, and the work people will see taking place over the next six months is evidence of that commitment," Walker said.