Access Porirua Transport Programme Business Case

The Access Porirua Transport Programme Business Case (PBC) will be used for transport infrastructure planning and will steer investment over the coming 10 to 15 years to address the opportunities and challenges of the changes occurring in Porirua City.

The Access Porirua Transport Programme Business Case (PBC) will be used for transport infrastructure planning and will steer investment over the coming 10 to 15 years to address the opportunities and challenges of the changes occurring in Porirua City.

The Porirua Growth Strategy 2048, adopted by the Council in March 2019, identifies the big issues we’re facing and takes a principles-based approach to dealing with those issues. That strategy has guided the development of this programme, with a particular focus on supporting an active and connected city. 

The PBC will be the Transport Implementation Plan for Porirua informed by the Growth Strategy. Once the PBC is finalized it will be used to inform the city’s District Plan and Long-term Plan (LTP).

The PBC has been developed in collaboration with the New Zealand Transport Agency (NZTA) and Greater Wellington Regional Council (GWRC). They are also key funding partners, since both are fundamentally concerned with the form and future operation of Porirua’s transport system, within the regional context.  

The points below highlight the key stages of development of the PBC.

Context of Change

Context of change. Various changes taking place in Porirua, including the opening of Transmission Gully Motorway in 2020, current and planned growth in housing development in response to shortages, and growth in economic opportunities (industrial, commercial, recreational tourism). Further changes are predicted as the recent capital and operational investments in transport systems (rail, bus, roads, ticketing and fares) take effect. 

Residential growth areas and expected household numbers in Porirua

Our Region is growning

Porirua has entered a unique period in the city’s history, with growth and change in transport, housing and commerce.

  • Transmission Gully (TG) presents a fundamental change to our transport system. The 27 kilometre four-lane motorway is an $850 million investment, Construction of Porirua’s two roads linking Whitby and Waitangirua to Transmission Gully motorway is underway and due for completion in 2020, which Council has invested $33 million to build . Transmission Gully has a regional impact but also locally influences the way people move within and out of the city. Its opening will result in changes for State Highway 1 and State Highway 58, altering both the usage and responsibility for these roads. This provides Porirua with a unique opportunity to take advantage of these changes by considering how the road can best serve Porirua residents.

  • Porirua is well placed to support regional housing demand. BERL Economics 2018 and the Greater Wellington Regional Council’s forecasts estimate the region’s population is likely to grow by an additional 172,300 people by 2048. This number of people will require approximately 66,000 new homes.

  • For Porirua, population growth scenarios (1) suggest that at a minimum there will be an additional 11,800 additional people living in the city by 2048, up to a potential maximum of 29,400 additional people. Porirua is well placed to bring housing land capacity on stream due to having a relatively good supply of greenfield land available.  Development to accommodate the expected population growth is a mixture of urban intensification / regeneration around public transport nodes, and greenfield development currently set further away from public transport. One of the largest new developments, in eastern Porirua, is the result of a $1.5 billion investment (2) by central Government, projected to result in an additional 2000 dwellings.

  • Tourism and recreation demand. Visitor demand (over 200,000 visitors each year) is expected to increase in Porirua once a proposed Adventure Park is operating (estimated to be in 2022).

  • Business trends reflect clear economic growth. Since 2010, 429 new businesses have established in Porirua, of which 156 started between 2015 and 2018. From 2010 to 2018 a total of 2,199 new filled jobs were created with 1,445 jobs created between 2015 and 2018. A significant proportion (and gross floor area) of new non-residential consents are for factories, industrial and storage buildings.

  • Commercial and industrial market requirements. Porirua has sufficient business floorspace capacity for commercial and industrial activities, however the location and accessibility of the existing capacity is unlikely to meet future market requirements. Additional land is therefore proposed to be rezoned for industrial and commercial use to meet long term demand.

  • Investments in regional transport system. Significant capital and operational investments in transport systems (rail, bus, roads, ticketing and fares) are changing the ways in which people move, and will continue to influence travel patterns.

(1) The National Policy Statement on Urban Development Capacity (NPS-UDC), September 2019 directs local authorities to provide sufficient development capacity to meet the projected demand for housing and business growth. The Ministry for Environment (MfE) used StatsNZ 2016 projections to determine Porirua’s growth classification as ‘medium’.


Responding to growth and change

Responding to growth and change. Porirua City Council is responding to the changes and growth that is taking place. The Growth Strategy will help shape and influence ‘why’ and ‘where’ the city will physically develop over the next 30 years and beyond. This PBC helps to develop one of the six key growth principles, namely, to have a connected and active city by enhancing how people move around the city and access opportunities. The Council is currently reviewing its District Plan so that it can continue to meet its obligations under the Resource Management Act 1991 (RMA)

Spatial framework from the Growth Strategy, showing a possible 30-year growth horizon

Responding to growth and change

The PBC has been developed to align with recent growth strategies and plans, including the Growth Strategy (2048) and the draft District Plan (currently being reviewed).

This approach has produced a possible future spatial framework for the city, although it is recognised that there are constraints that may inhibit this framework being realised within the 30-year timeframe. 

Within the existing urban area, the Growth Strategy has a strong focus on compact, more intensive housing development centered around public transport hubs and established urban centres. It therefore promotes more efficient use of already developed urban land, which is also a key factor in creating more affordable housing. It also promotes investment in multi-modal transport options to support higher residential densities and reduce reliance on private vehicles.

The PBC has been developed with these principles and intentions as a key success factor, underpinning the development of a connected and active city.

Strategy and planning

Strategy and planning. A sequencing plan has been developed to assist with sustainable development and timing uncertainties. This guides the conversation about allocating resources and managing the effects of development.  

Projected growth sequencing for Porirua over 30 years

Porirua growth

We have developed a growth sequencing plan to assist with sustainable growth including uncertainties of exactly when developments will occur and what their impacts will be. This will help to guide conversations about allocating resources at the appropriate time and managing the transport and environmental effects of development.

Some developments are more certain than others, for example, TG opening is 100% certain whilst growth in dwelling numbers and their completion dates naturally become less certain the further ahead we look. However, in the very short term (to 2023), up to 1,650 household units will become available in Kenepuru, Whitby, Aotea, eastern Porirua Development and Plimmerton Farms. Over the medium term (until 2033) there is an estimated additional 5500 new dwellings becoming available in Plimmerton Farms, Gray Farms, Pukerua Bay and eastern Porirua.

The modelled effects (3) of various residential growth scenarios as well as the effect of Transmission Gully on Porirua’s roading network clearly indicate that any relief in traffic resulting from TG is short-term and will be taken up with additional trips associated with new development.  This provides Porirua with an opportunity to take advantage of these changes by considering how the current State Highway One and Fifty Eight can best serve Porirua residents, by improving the livability of its streets, towns and communities and by reconfiguring the network to be more connected, sustainable and active.

(3) The PBC utilised the existing North Wellington Saturn transport Model (NWSM) to forecast the effects of various growth scenarios, up to the year 2041. 

Investment objectives

Investment objectives. The Council recognizes that growth creates challenges and opportunities. The specific challenges (problems) and opportunities (benefits) relating to transport have been assessed and captured as a suite of Investment Objectives.

Relationship between identified problems and benefits coming from intervention and investment 

Investment objectives

The current and forecast changes and growth will create specific challenges and opportunities relating to transport, and there is merit in considering investments which address them. In terms of road safety, Porirua local roads are quite safe, ranking 68th out of 70 districts in New Zealand for severity of risk for all deaths and serious casualties.

However, the transport networks will need to change to support the population and geographic growth in the city.  This is highlighted by the challenges and problems as follows:

  • Due to the layout of the city and the distance of most suburbs from public transport, walking and cycling are generally not seen as attractive modes of transport.
  • Current networks are not optimised for future travel demand, while poor access to core bus and rail services reduces travel choice for parts of the city.
  • If all the proposed developments proceed, travel times and delays using existing key transport networks will increase, even with Transmission Gully in place.
  • The further out from the city centre, the greater density of households with two or more cars. This coincides with urban developments having poor accessibility to rail transport. Residents need to drive to a park and ride facility or travel into Wellington via private car, exacerbating existing stress points (Mungavin Avenue, Kenepuru, and Whitford Brown Avenue).

These problems are captured below, along with the benefits of addressing these problems. The benefits effectively define the investment objectives for Porirua.

Preferred strategic response

Preferred strategic response. We want to develop an active and connected city focussing on providing better access to key destinations for employment, housing and economic growth areas in the city, and transport connections such as rail stations. It also aims to support housing growth areas and economic growth.

General transport network for Porirua, showing some of the key destinations and transport linkages 

preferred strategic response

The preferred response, to deliver on the investment objectives, is to develop an active and connected city as supported in the Growth Strategy. This focusses on providing better access to key destinations such as employment areas in the City, and transport connections such as rail stations. It also aims to support proposed housing growth areas and economic growth. 

A fundamental requirement of this outcome will be the reconfiguration of sections of SH1 and SH58 (following opening of Transmission Gully), to align with the network requirements and community expectations. 

In terms of the approach taken to identify the preferred programme, a range of proposed projects were identified and developed which address the investment objectives and which respond to the varied influences facing Porirua.  

An initial long list of eight programmes was developed which respond to the investment objectives identified. These eight programmes are:

  • Support urban intensification;
  • Focus on access to railway stations;
  • Support growth of eastern Porirua;
  • Respond to effects or opportunities arising from Transmission Gully motorway;
  • Address network resilience;
  • Support north-western growth area;
  • Support northern growth area; and
  • Supports city centre.

Through the assessment process, the programme which best supports urban intensification was identified as the preferred option. It seeks to: 

  • support urban intensification around the public transport nodes identified in the Growth Strategy for the medium term
  • support urban intensification at the compact regeneration areas identified in the Growth Strategy. 

This focus means it has a large geographical effect across the city and includes transportation projects that seek to:

  • improve movement and access within and to the central city
  • improve conditions for walking, cycling and public transport interchange in the central city and compact regeneration areas
  • improve station access including conditions for walking and cycling at Plimmerton, Mana, Paremata and Porirua
  • improve movement of people along key corridors in the city including Kenepuru Drive, Whitford Brown Avenue, Titahi Bay Road, Warspite Avenue & Mungavin Avenue
  • provide bus priority at Cannons Creek and on the approach to the Mungavin interchange
  • improve level of service for the rail connection between Wellington and Plimmerton
  • improve levels of service for bus connections between Porirua City Centre and eastern Porirua
  • improve levels of service for bus connections between Paremata, Mana and Whitby.

Whilst the preferred programme is broad across the entire city and covers several projects, it also addresses long-term issues (up to 2048). The initial priorities over the coming 3 years will likely focus on:

  • Commencement of the Business Case for SH revocation and reconfiguration. This project is wide-ranging in terms of community involvement and will also cover a range of workstreams including traffic / transportation, environmental, economic and social.
  • Ongoing development of the Business Case for the Kenepuru Corridor and completion of initial projects there. The Business Case responds to the effects of Transmission Gully connecting to Kenepuru Drive and short-term development pressures. At the same time it considers how the transport network can best support ongoing development in the Kenepuru area by improving accessibility and connections into the CBD and wider Porirua City.
  • Negotiation and agreement with NZTA, GWRC and the eastern Porirua development project on their alignment with and contributions to the PBC work.
  • Commencement of Station Access Masterplans for priority train stations (Porirua, Kenepuru, Plimmerton), so that accessibility is enhanced and future development is sustainable and supportive of Porirua’s preferred outcomes.
  • Development of key analytics tools which will provide further evidence in support of business case development and investment/funding proposals.   
  • Ongoing operational improvements through the Low Cost Low Risk (LCLR) programme, which improves the level of service for all users.  
  • Development of policies (e.g. micro-mobility partnerships, or future parking management) which support improved access or supply, whilst reducing car dependency including school travel.
  • Preparation of a bus network review, in anticipation of developments increasing demand.

Preferred programme of investment opportunities

Preferred programme of investment opportunities. This covers a range of possible future investments across the city, using a variety of transport options including cars, buses, rail, walking and cycling as well as the more recent “micro-mobility” options such as e-scooters.

Preferred programme of investment opportunities in Porirua 

preferred strategic response

The candidate projects within the preferred programme are illustrated below.

These are effectively the investment opportunities which the funding partners could consider, in order to address the current and future challenges within Porirua.

The way forward

The way forward. For effective implementation, the funding partners must align their investment priorities and support this programme through the allocation of resources. This will be addressed and confirmed through the preparation of the Long-term Plan, and subsequent regional and national Land Transport Programmes.

Anticipated investment costs and benefits 

Anticipated investment costs and benefits

Key Dates: The following timeline is planned for the PBC:


Overall responsibility for delivery of the programme will rest with Porirua City Council.  However, the integrated nature of the programme, in terms of public transport aspects (GWRC) and the aspects relating to local road/state highway integration including Transmission Gully (NZTA), means that the accountability does not rest solely with PCC.

The Transport Agency and GWRC are key funding partners, and both are also fundamentally concerned with the operation of a sustainable transport system for Porirua, within the regional context. 

Therefore, for effective implementation the funding partners must align on the local and regional investment priorities and support the programme through allocation of resources. This will be addressed and confirmed through the preparation of the Long-term Plan, and subsequent regional and National Land Transport Programmes.

Investment can be split broadly into three main categories: Infrastructure, Public Transport, and Active, with investment coming from NZTA, GWRC, and Porirua City Council.  Some additional funding will inevitably come from HLC (4) as part of the eastern Porirua Development.

Infrastructure relates to local roading and state highways, including improvements to known and potential hot spots. Public transport investment looks at improving access to buses and trains, while Active investment aims to make cycling and walking around the city more attractive. 

Cost estimates for a Business Case which addresses SH revocation and local road reconfiguration are included, however specific investments relating to physical works are not known at this stage and therefore not included.

(4) Homes Land Communities (HLC) is a subsidiary of Housing New Zealand and responsible for managing the project in eastern Porirua.

Your privacy

All submissions are public information. This supports our drive to be as transparent as possible, but, if there are any personal details you don’t want made public, please let us know.

How you can have your say

Feedback must be received no later than 5pm Friday 25 October 2019.

Your feedback can be emailed to  Please include "Access Porirua" in the subject line.