This is an HTML version of an attachment to the Official Information request 'Benefit to Cost Ratio and Reasons for Variance - Transmission Gully Project'.

50  Victoria Street 
Private Bag 6995 
Wellington 6141 
New Zealand 
T 64 4 894 5400 
F 64 4 894 6100 
11 March 2020 
Mr Brian Warburton 
[FYI request #12245 email] 
REF: OIA-6409 
Dear Brian 
Request made under the Official Information Act 1982 

Thank you for your email of Saturday 15 February 2020 requesting the following information under the 
Official Information Act 1982 (the Act): 
1.  Benefit/Cost Ratio – please provide details of the 
the benefit/cost ratio as determined by NZTA for the Transmission Gully Project when it 
was first designated in 1999; 

the benefit/cost ratio as determined by NZTA for the Transmission Gully Project when it 
was subsequently re-designated in 2012; 

the benefit/cost ratio as determined by NZTA for the Transmission Gully Project 
immediately prior to the recent reassessment announced mid-February 2020) of the 
transport funds required to complete the project; and, 

the benefit/cost ratio as determined by NZTA for the Transmission Gully Project after its 
recent reassessment (announced mid-February 2020) of the transport funds required to 
complete the project (i.e.: after the incorporation of an additional $190M to the cost of 
the project). 

2.  Variance 
Please provide me with sufficient information so I am to understand: 
if, in respect of 1c and 1d, there is a variance of more than 5% between the cost of the project 
what the reasons are for that variance; and, 

if, in respect of 1c and 1d, there is a variance of more than 5% between the benefits of the 
project what the reasons are for that variance. 

Regarding your specific requests for details on the benefit/cost ratio (BCR) as determined by Waka 
Kotahi NZ Transport Agency for the Transmission Gully Project, our responses are as follows: 
1(a) –   We have reviewed historic records, despite reasonable and considerable efforts to try and 
locate a document that identifies the benefit/cost ratio for Transmission Gully when the Notice 
of Requirement was lodged in 1996 and/or designated following appeal in 2003. We have 
been unable to locate any document(s) containing the information requested, therefore your 
request is being refused pursuant to section 18(e) of the Act on the basis that the document(s) 
containing the information requested cannot be found, despite reasonable efforts to locate 
1(b) –   The Transport Agency stated in evidence to the Board of Inquiry hearing in 2012 for the 
Transmission Gully motorway that the BCR for Transmission Gully was 0.82, excluding 
agglomeration benefits.   
That BCR is contained in a brief of evidence available at the following website, covered in 
pages 97 to 106:

In 2013, the BCR for the Wellington Northern Corridor was recalculated as part of an 
addendum to the Business Case for the Wellington Northern Corridor. The BCR for the 
Wellington Northern Corridor was 1.6 including agglomeration benefits, but without wider 
economic impacts and 1.8 including wider economic impacts.  The benefits and costs of the 
Transmission Gully project are included within the corridor BCR.  The calculated Transmission 
Gully Project BCR at that time was 1.5 as a stand-alone project. 
A copy of the updated Wellington Northern Corridor Business Case: 2013 Addendum is 
available at

In response to your requests numbered, 1(c), 1(d) and 2, the BCR for Transmission Gully has not 
been recalculated since 2013. These requests are therefore refused pursuant to section 18(e) of 
Act on the basis that the information requested does not exist.   
Under section 28 of the Act, you have the right to ask the Ombudsman to review my decision to refuse 
parts of your request. The contact details for the Ombudsman can be located at 
If you would like to discuss this reply further with the Transport Agency, please contact Craig 
Nicholson – Principal Project Manager Transmission Gully, by email to [email address] 
or by phone on (04) 910 8183. 
Yours sincerely 
Tony Fisher 
Acting Senior Manager, Project Delivery