50 Victoria Street
Private Bag 6995
0
Wellington 6141
New Zealand
T 64 4 894 5400
F 64 4 894 6100
www.nzta.govt.nz
11 August 2022
Jack Gibbons
[FYI request #19864 email]
REF: OIA-10505
Dear Jack
Request made under the Official Information Act 1982
Thank you for your email of 9 July 2022 requesting information about the State Highway 1 (SH1)
Waikato Expressway’s 110kmh speed limit under the Official Information Act 1982 (the Act). I will
address each of your queries in turn.
1) The Economic Evaluation / Business Case.
Waka Kotahi NZ Transport Agency undertakes a benefit cost analysis as part of the wider Speed and
Infrastructure Programme, but not of speed reviews on their own. The Speed and Infrastructure
Programme is not required to have individual project Benefit Cost Ratios, as the Programme is
principle based and seeks to implement a balanced response to the risk in the transport system.
Assurance of value for money is provided by the use of standard safety interventions and the
programme-level economic assessment that demonstrates value for money.
As such, I am refusing this part of your request under section 18(e) of the Act as the document al eged
to contain the information requested does not exist.
2) The Environmental Impact Review (including co2e and other pollutant gas predictions).
Please refer to Attachment 1.
To provide further context, Waka Kotahi has information in the enclosed document on greenhouse gas
(GHG) emission estimates for the 110km/h speed limit based on available traffic model ing data for
2031 and 2041 for vehicles using the Tamahere to Hampton Downs section of the Waikato
Expressway.
The findings show that if we assume an increase in average fleet speed of 10km/h to 110km/h, this will
result in a predicted increase of 4.34 percent and 3.77 percent in GHG emissions for years 2031 and
2041 when compared to 100km/h.
The main reason for the predicted increase in GHG emissions is due to light vehicles (for example,
passenger vehicles) driving at 110km/h and operating beyond their optimal fuel efficiency of around
75km/h. The reduction between 2041 when compared to 2031 is due to expected improvement in
average fleet emissions over time.
Waka Kotahi uses the Vehicle Emissions Prediction Model (VEPM) to estimate fleet average
emissions from vehicles in the fleet, based on their average speed and typical road, traffic and
operating conditions, such as weather. There are limitations of this approach given the complexity of
calculating real world fuel consumption of vehicles as discussed above.
Further information on the model can be found here: www.nzta.govt.nz/roads-and-rail/highways-
information-portal/technical-disciplines/air-quality-climate/planning-and-assessment/vehicle-emissions-
prediction-model/.
3) The Road Safety Audit (including for walking and cycling).
Please refer to Attachments 2 to 7.
Certain information in Attachments 1, 2, 3, 5, 6 and 7 have been withheld under section 9(2)(a) of the
Act to protect the privacy of non-Waka Kotahi natural persons, including that of deceased natural
persons.
With respect to the information that has been withheld, I do not consider there are any other factors
which would render it desirable, in the public interest, to make the information available.
Under section 28 of the Act, you have the right to ask the Ombudsman to review my decision to
partially withhold this information. The contact details for the Ombudsman can be located at
www.ombudsman.parliament.nz.
If you would like to discuss this reply with Waka Kotahi, please contact the Speed and Infrastructure
Programme team, by email to [email address].
Yours sincerely
Mark Kinvig
National Manager Infrastructure Delivery
2
OIA-10505 Document Schedule
REF Document name
Date
Information being withheld/reason
for withholding
1. WEX Greenhouse Gas
2 September
Staff phone numbers are withheld
Emission Change Rev 2
2021
under s9(2)(a) to protect their
(100110km)
privacy.
2. RSA SH1 WEX Detailed Design 7 October
Third party names and contact
- Designer, Safety Eng, Client
2016
details are withheld under s9(2)(a) to
response
protect their privacy.
3. WEX 110 Hampton Downs -
29 September Third party names and contact
Design RSA - Designer, RSE,
2021
details are withheld under s9(2)(a) to
Client Response
protect their privacy.
4. WEX 110 Ohinewai - Design
30 November
N/A
RSA and Memo - Designer,
2020
RSE, Client Response
5. WEX 110 Ohinewai - Post
26 May 2022
Third party names and contact
Construction RSA - Designer
details are withheld under s9(2)(a) to
Response
protect their privacy.
6. WEX 110 Ngāruawāhia - RSA
2 March 2022 Third party names and contact
details are withheld under s9(2)(a) to
protect their privacy.
7. WEX 110 Tamahere - Design
26 October
Third party names and contact
RSA - Designer, RSE, Client
2021
details are withheld under s9(2)(a) to
Response
protect their privacy.
3
