Contents: History | The Improvements | Why These Improvements?

The North Western Motorway

The North Western Motorway is the second shortest motorway in Auckland, after the South Western Motorway. It stretches 18km in a north-west direction between Parnell in Auckland City to West Harbour in Waitakere City. The first section opened in 1955 between the current Waterview Interchange and Lincoln Interchange, mainly as a means of access to Whenuapai Airport. Between 1957 and 1961 the motorway was extended to Westgate, where it currently terminates. In 1979 a small section between Newton Road and St Lukes Road was completed, followed with connections to the newly completed Central Motorway Junction only to Hobson and Nelson Street. In 1983 all gaps were filled to allow a complete motorway between Hobson Street and Nelson Street.

Recent History: In 1988 the heavily used North Western to Southern Motorway ramp opened, followed in 1989 with the Grafton Gully links to Wellesley and Stanley Street. In the mid 1990s the motorway was widened and the Rosebank and Patiki ramps were added. In 2003 the Grafton Gully upgrade project completed offering better links to Wellesley Street and Stanley Street. In 2006 following the completion of the Central Motorway Junction added the Northern Motorway links and a fourth lane was added between Newton Road and St Lukes Road. Ramp Signalling has been functioning on most on-ramps since 2009. The Upper Harbour Hobsonville motorway project, due for completion in 2012, extends the North Western Motorway to Brigham Creek Road.

Relation to the Western Ring Motorway: A large part of North Western Motorway will become a section of the Western Ring Motorway. Which will create an alternative to the overloaded Southern and Northern Motorways via the western motorways of Auckland. To make this alternative worthwhile during peak times, this section of the North Western must be upgraded to handle the extra traffic volume.

The Improvements

Under Planning | $100m+ | Start Date: 2009 to 2011

The improvement project will offer:

- Addition of one or more lanes in both directions between St Lukes Road and Royal Road.
- Improvement of and widening of interchanges; particularly Te Atatu and Lincoln Interchanges.
- Improved public transport along the corridor; i.e. bus lanes.
- Improved pedestrian and cycling access along and across the motorway.
- Raising of the Causeway (between Waterview and Rosebank Road) to prevent flooding.
- Improved results from Ramp Signalling through improvement of the on-ramps and surrounding features that influence the effectiveness of the signals.
- Cater for increased traffic from the completion of the Western Ring Motorway.

Note: This project is in early stages. Definite and highly technical information is not available yet.

Above: Overview of the improvement section, with interchanges.

Changes to lanes:

- Citybound; between Westgate and the Te Atatu interchange will be widening from two lanes to three lanes. From Te Atatu to St Lukes will be widened from three lanes to four lanes wide.
- Westbound; between St Lukes and Waterview three lanes will be widened to four lanes. Between Waterview and Rosebank (causeway) three lanes will be widened to five. From Rosebank to Te Atatu three lanes will be widened to four. The remainder to Westgate will be widened from two lanes to three.
- Overall the whole section will receive more lanes in each direction.

Why these improvements?

The North Western Motorway is a short motorway that serves large volumes of traffic. It provides access to large residential areas of Waitakere City, industrial and commercial areas around Rosebank and Lincoln Road, provides an alternative route north and in the future will handle a section of the Western Ring Motorway.

Congestion: Currently the North Western Motorway has some of the worst PM peak traffic in Auckland. Often the motorway will be bumper to bumper between Central Motorway Junction and Lincoln Road (almost the whole length). The future demands expected of the motorway will not be able to cope with increased traffic, especially when the Western Ring Motorway is complete. Widening the motorway will allow for increased capacity - more room for traffic that is exiting at interchanges and dedicated straight through lanes for vehicles on longer journeys.

Interchanges: Observations of the North Western Motorway in PM peak shows that congestion is caused by tailing of queues exiting the motorway - because the interchanges cannot cope. This tailing causes congestion on the motorway, thus slowing down straight through traffic. Interchanges are the overriding problem of the North Western motorway. Particularly the St Lukes, Te Atatu and Lincoln off-ramps, which are short, narrow and do not suit the changes in traffic that has occurred since their construction. Improvements to the interchanges will improve how traffic can quickly exit the motorway without causing tailing. This will mean wider and longer off-ramps, improved arterial roads and intersection improvements.

Public Transport: Improved access for buses will allow more options for commuters. This will include dedicated bus lanes to allow faster and more reliable travel times for buses.

Flooding: Currently the Causeway (the section between Waterview and Rosebank Road) is sinking due to the poor base that the motorway has been laid on. It is also too low for expected changes in sea level, higher tides and pressure systems. The Causeway will be raised and reinforced.

Western Ring Motorway: Improvements must be made to allow for a valid alternative, and the increased traffic that will use the North Western Motorway must be accommodated for without causing significant issues for the current traffic that uses the North Western.