50 Victoria Street
Private Bag 6995
Wellington 6141
New Zealand
T 64 4 894 5400
F 64 4 894 6100
www.nzta.govt.nz
18 November 2022
Rhys Lewis
[FYI request #20846 email]
REF: OIA-11208
Dear Rhys
Request made under the Official Information Act 1982
Thank you for your email of 13 October 2022 requesting the following information under the
Of icial Information Act 1982 (the Act):
Could you please tell me the percentage of roading maintained by NZTA that is currently
over the design life duration for the seal grade and traffic volumes that apply to that
section of road.
The attached document
OIA-11208 Results falls within the scope of your request.
By square meterage of major surfaces, 32% of the network is overdue for renewal based on
the design life (where available) or the default/modified life (where design life is
unpopulated). For context, please note that design lives are approximations only and that
results with an overdue status are subjective.
As an industry, we use the NZ Chip Sealing Manual to set our expectation around design
lives. These design lives have not been adjusted for some time but are the defaults we
general expect to achieve if traffic volumes and traffic mix stayed constant over time.
It is important to highlight that the design life is indicative only and that our renewals and
resurfacing programmes are reviewed and refined annually. We do this using asset data,
high speed data collection tools, surfacing data and best practise, to identify highest priority
and need. There are instances when a pavement may exceed design life but condition is
meeting standards and level of service, therefore a treatment is unnecessary.
Significantly, our 2021-22 resurfacing and renewal programme successfully achieved 2,119
lane kilometres, our most achieved in one season, and we are aiming even higher in 2022-23
with a programme target of 2,587 lane kilometres across Aotearoa.
If you would like to discuss this reply with Waka Kotahi, please contact us by email to
[NZTA request email].
Yours sincerely
Vanessa Browne
National Manager Programme and Standards
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