This is an HTML version of an attachment to the Official Information request 'Motorway costs'.

23 October 2019 
Barry Garrick  
[FYI request #10943 email] 
Ref: NZT-4391 
Dear Barry 
Thank you for your email of 1 October 2019 about cost estimates for projects mentioned in a 2017 
political party announcement.  
Below is information about four laning in the corridors you identified: 
Wellsford to Whangarei 
I can confirm that a four-lane motorway was never planned by the NZ Transport Agency for State 
Highway 1 (SH1) between Wellsford and Whangarei.  
East West Link in Auckland 
Four laning was considered for the East West Link and the cost estimate for the project was $1.25 -
$1.85 billion. The business cases for this project are available on our website and can be accessed at 
Cambridge to Tirau 
While the Transport Agency does not have a project identified as Cambridge to Tirau, we do have the 
Cambridge to Piarere project and the Piarere to Taupo project.  
•  Cambridge to Piarere 
An Indicative Business Case for the Cambridge to Pairere Long Term Improvements was 
completed in 2017. This advised that the indicative costs were in the range of $390 million to 
$620 million.   
•  Piarere to Tirau 
The Transport Agency completed this work in 2016, as part of a business case considering 
SH1 from Piarere through to Taupo, which confirmed the need for improvements on SH1 
between Piarere to Tirau. This work recommended safety both short term improvements and 
more significant transformational improvements in the medium term (10 to 20 years) when 
traffic volumes increase, and safety triggers are met.  Whilst further work is needed to confirm 
the form of improvements, the business case suggested that a 2+1 lane arrangement may be 
appropriate through to Taupo. 
Piarere to the foot of the Kaimai Range 
The 2016 Programme Business Case (PBC) confirmed safety and efficiency problems that impact on 
the ability of State Highway 29 to function as a National (high volume) road. In particular, the section 
of State Highway 29 over the Kaimai Range has a sub-standard safety record, poor resilience and a 
higher cost of travel due to steep gradients. 
The PBC recommended a programme of improvements that included intersection upgrades, passing 
lane improvements and a realignment of the road over the Kaimai Summit to lessen the impact of the 
steep grade. These improvements are expected to result in a more consistent journey that will make 
State Highway 29 (with the State Highway 1 Waikato Expressway) the preferred route for inter-
regional travel between Auckland and Tauranga.  

Four laning was not a recommendation within the PBC. 
Tauranga to Katikati 
Four laning for Tauranga to Katikati was only ever considered at the 2016 PBC stage as part of a 
long-list of options. As a good portion of the Tauranga to Waihi corridor is rural and the project 
objectives mostly revolved around safety, four laning past Omokoroa and out to Katikati never made 
the short-list so was not investigated any further. 
Napier to Hastings 
No work has been done by the Transport Agency to estimate the costs to four lane the entire corridor 
from Napier to Hastings. 
Manawatu Gorge 
On 15 October 2019 the Transport Agency announced that the new Te Ahu a Turanga: Manawatū 
Tararua Highway will be two lanes each way for the majority of the new road, including the plateau 
across the Ruahine Ranges. This project has an estimated cost of $620 million. 
Levin to Sanson 
No work has been done by the Transport Agency to estimate the costs to four lane the corridor from 
Levin to Sanson.  
Christchurch Northern Motorway 
An overview of the Christchurch Northern Corridor projects and the estimated project cost are 
available online at I 
can confirm that no cost estimates were created in 2017 for four laning of the section of the road north 
of the Waimakariri River. 
Christchurch to Ashburton 
Christchurch to Ashburton has never been a Transport Agency project and no work has been done to 
assess the cost of four laning between Rolleston and Ashburton. 
If you would like to discuss this reply with the NZ Transport Agency, please contact Ministerial 
Services by email to [email address]. 
Yours sincerely 
Robyn Elston 
Senior Manager, System Design