44 Bowen Street
Private Bag 6995
Wellington 6141
New Zealand
T 64 4 894 5400
F 64 4 894 6100
www.nzta.govt.nz
13 May 2026
Nigel Gray
[FYI request #34473 email]
REF: OIA-21856
Dear Nigel
Request made under the Official Information Act 1982
Thank you for your email
of 11 April 2026 requesting the fol owing information under the Official
Information Act 1982 (the Act). I will respond to parts of your request in turn as fol ows:
A. Medical‑
Event Crashes (2023, 2024, 2025) For each of the last three calendar years,
please provide:
The number of fatal crashes where the primary contributing factor was recorded as a
medical event.
The number of serious‑
injury crashes where the primary contributing factor was a medical
event.
The number of minor‑
injury crashes where the primary contributing factor was a medical
event.
The Crash Analysis System (CAS) does not have a “primary contributing factor” as there is no
hierarchy.
The fol owing document falls within the scope of your request and is enclosed:
• Attachment 1 – Crash data – medical events and drugs 2023-2025
(spreadsheet).
The number of fatal crashes removed from the official road‑
toll dataset because they
were determined to be caused by a medical event.
Based on information from our Crash Analysis System (CAS), the number of deaths provisional y
excluded from the official road death statistics, due to a medical event for years 2016 to 2025
inclusive, is outlined in a table on the following page:
Year
Number of Deaths
2016
24
2017
24
2018
19
2019
29
2020
30
2021
20
2022
33
2023
23
2024
22
2025
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Excluding deaths (as an
“Excluded – medical event”) from road death statistics is provisionally agreed
by Ministry of Transport Te Manatū Waka, New Zealand Police and NZ Transport Agency Waka
Kotahi (NZTA). Agreement is based on medical evidence provided to New Zealand Police
investigating officers (for example, medical history or preliminary post-mortem results). However, the
actual cause and manner of death is ultimately a decision for the Coroner, and provisional exclusion
decisions may be confirmed or reversed following the Coroner’s findings.
It is also important to note that there are limitations with this information:
• Recording of the reason for exclusion has been inconsistent over time. Our data team has advised
that data from 2023 onwards is reliable, but earlier years may be incomplete.
• To compile the historic figures, the data team reviewed information from a range of sources (which
includes CAS, correspondence between NZTA and New Zealand Police, Police Serious Crash
Unit reports, and Coroner’s findings). Even with this work, there remains a possibility that some
cases may have been missed.
• Some crashes involving a death that was excluded may not appear in the CAS database and,
where a fatality is excluded, the crash severity recorded in CAS may be classified at the next-
highest injury level.
Information is also held by the Ministry of Transport and is published on its website at:
https://www.transport.govt.nz/statistics-and-insights/safety-road-deaths
The Ministry holds data which relates to deaths that have been excluded from the official road death
statistics due to different reasons (for instance; a suicide, or that a crash occurred in an offroad area
because of a medical event). If you click on the
“Daily updated provisional road deaths” tab on the
website, then click on the
“All data” tab in the table, then scroll down and move the horizontal bar at
the bottom of the table to the right, you wil see a column which denotes if the death is included (true
or false). The Ministry does not publish the reason for the exclusion.
The exact Police or CAS factor codes, definitions, or descriptors used to classify a crash
as a medical event.
Information for this part of your request is outlined in a table on the fol owing page:
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Code
Definition
Description
504
Medical illness
Used when a driver or road user (including pedestrians) indicates
that they suffered symptoms of an illness which they were aware of.
This includes epilepsy, colds and other illnesses for which drugs are
being taken.
501
Sudden il ness
Used when a driver or road user (including pedestrians) indicates
that they suffered an illness which they had no prior knowledge of –
for instance; heart attacks, epilepsy, blackouts, food poisoning and
aneurisms which a person had not experienced before.
The code can also be used for il nesses that a person knows about
which they take prescription drugs for, and the il ness is believed to
be under control. The code also applies for coughing, sneezing,
vomiting and cramps.
The number of cases currently coded as “suspected medical event” or equivalent where
coronial findings are pending.
This information is not held by NZTA. I am therefore required to refuse this part of your request under
section 18(g)(i)) of the Act as the information requested is not held by NZTA, and there is no reason to
believe that it is held by another department or organisation.
B. Drug‑
Related Crashes (2023, 2024, 2025) For each of the last three calendar years,
please provide:
The number of fatal crashes where drugs were recorded as a contributing factor.
The number of serious‑
injury crashes where drugs were recorded as a contributing factor.
The number of minor‑
injury crashes where drugs were recorded as a contributing factor.
The number of fatal crashes where both alcohol and drugs were contributing factors.
The factor codes, definitions, or descriptors used to classify drug involvement.
Information for these parts of your request is outlined in Attachment 1.
The number of cases initial y coded as “pending toxicology” that were later updated to
“drug‑
related.”
As the CAS database only shows the current state of a crash report, we would not be able to confirm if
a record had been previously recorded as
“pending toxicology” and then updated.
I am therefore required to refuse this part of your request under section 18(g)(i) of the Act as the
information requested is not held by NZTA, and there is no reason to believe that it is held by another
department or organisation.
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C. Classification and Data‑
Handling Procedures Please provide:
The internal Police guidance, instructions, or criteria used to determine when a crash is
classified as:
a medical event
drug‑
related
alcohol‑
related
excluded from the official road tol
Any procedures or thresholds used when updating crash records following coronial
findings or toxicology results.
This part of your request was transferred to NZTA by New Zealand Police, who advised us that it does
not hold the information you are seeking for this part of your request.
As NZTA or New Zealand Police does not hold any such information, I am therefore required to refuse
this part of your request under section 18(g)(i) of the Act as the information requested is not held by
NZTA, and there is no reason to believe that it is held by another department or organisation.
We can, however, advise that, while NZTA holds information that gives guidance on classifying crash
records, New Zealand Police also includes information about a specific crash in a traffic crash report
(TCR) when they send it to us. New Zealand Police also records drug and alcohol test results and
comment in TCRs that, for instance, a driver experienced a medical event.
E. Administrative Notes
[…]
If coronial delays affect final classification, please provide the current Police coding and
note which cases are pending.
NZTA does not hold any information regarding coding used by New Zealand Police. We also
consulted with New Zealand Police who advised that it does not hold this information.
I am therefore required to refuse this part of your request under section 18(g)(i) of the Act as the
information requested is not held by NZTA, and there is no reason to believe that it is held by another
department or organisation.
We can, however, advise that NZTA codes crashes whereas New Zealand Police do not. Instead,
New Zealand Police provide a narrative for a TCR to explain what happened, and we only know about
this if the Coroner has given a ruling for a fatal crash when we receive a copy of the findings.
It is important to note that, as not all deaths from crashes are referred to the Coroner, NZTA has no
knowledge of what might be pending. This would need to be referred to the Coroner’s Court.
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Under section 28 of the Act, you have the right to ask the Ombudsman to review my decision to refuse
parts of this request. The contact details for the Ombudsman can be located at
www.ombudsman.parliament.nz.
In line with NZTA policy, this response will soon be published on our website, with personal
information removed.
If you would like to discuss this reply with NZTA, please contact Ministerial Services by email to
[email address].
Yours sincerely
Josh Driscoll
Manager, Ministerial Services
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