MIN-4332 Road Maintenance
30 November 2023
Provide information on the importance of road maintenance, how roads support economic growth & improve
productivity and the amount of potholes and need to invest more in road maintenance
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NZ Transport Agency’s response:
The state highway network is New Zealand’s largest value social asset and is of critical importance to the
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country’s social and economic outcomes. Approximately 90% of the state highway network continues to meet
minimum asset condition requirements and is performing as expected. The other 10% is near or below the
level of what is considered acceptable. This is impacting the level of service experienced by road users
through increased exposure to uneven road surfaces, potholes, and journey disruption, such as that caused
by landslide events. When lifeline routes are affected, significant detour routes can be required and, in some
cases, no alternate is available.
The roading network serves an important purpose because it allows people and goods to get to places where
they can access services, engage in social interaction, or their place of work and then back home. It enables
goods to be distributed throughout the country to the end users or to ports for export. Our social and economic
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wellbeing depends on roads because our standard of living depends on access to the services we need and
the goods that we consume and enjoy.
Most goods that are exported travel ed by road at some point from raw material to factory, to port. This travel,
regardless of mode or reason, needs to be reliable, safe, easy and cost effective to make when convenient, so
the state highway network and transport system need to be available and in good order. This requires
continued maintenance of the transport system.
Roads have suffered from a lack of maintenance and their condition has deteriorated to a level where more
work is required to bring them back to an acceptable condition. There has been a noticeable increase in
potholes on sections of the state highway network over the past few years, which has been portrayed as a
significant representation of the general condition of the wider network.
Ongoing under-investment in preventive measures is resulting in repeated cycles of damage and repair. While
we are managing the asset well overal and within funding constraints, a lack of preventive investment on
items such as subsoil drains or culverts means that infrastructure such as pavements deteriorate faster and
the cost of recovery from extreme weather events and other disruptions is higher and more work is required to
bring it up to condition.
Most potholes form during the wet winter months. While there is currently no data available for winter 2023,
there was a significant increase in the number of potholes repaired on the state highway network in the winter
of 2022. During the 2021/22 financial year over 45,000 potholes were repaired across the state highway
network in comparison to approximately 36,000 over the same period in the 2020/21 financial year.
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Traffic volumes are increasing. Freight model ing from Ministry of Transport shows that the upper North Island
freight task has grown substantially since 2018 and is expected to keep growing to a 45% increase by 2033.
Therefore, we need to get the structure of road right when we do maintenance so that it is durable into the
future, despite increasing freight.
Degraded road surfaces and increased rainfal makes it more likely for water to enter the pavements making
them weaker and more vulnerable to damage from heavy vehicles and increasing the rate at which potholes
form and greater decay occurs. We need to reduce the vulnerability to roads by increasing our preventive
maintenance works such as drainage and resurfacing our roads so they shed water.
Over the past ten years the length of state highway has grown by 10%, increasing the assets being
maintained and traffic by 15% which has increased the load and rate of deterioration of infrastructure. This
means that every bit of maintenance delivered needs to be of best value. Therefore, not just fixing potholes,
but also stop them forming. This requires that we do the right works when we maintain our roads so that we
make them robust and durable and less vulnerable to damage. This involves strengthening our road ACT 1982
pavements not just resurfacing them. To do this, we also need to have the right information available about
which roads are deteriorating and where we should undertake the right works, in the right places at the right
time.
To make the challenge manageable, we need to hold and maintain those roads in better condition whilst we
focus on fixing the roads in poor condition. The NZ Transport Agency has developed a ten-year programme
that wil gradually increase the level of rehabilitation (alongside other renewal activity) to achieve an
acceptable level of service across the entire state highway network by 2033. This programme is subject to the
funding level provided for the State Highway Maintenance Activity Class over the next three NLTPs.
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