The Ngauranga to Aotea Quay project (NtAQ) is part of the Wellington Northern Corridor. The three kilometre section of SH1 between Ngauranga and Aotea Quay is the most congested part of Wellington’s motorway network. Traffic build-up during morning and afternoon peak times means long queues, low speeds and variable travel times along this section of SH1, as well as on the surrounding roading network. A crash or other hold up can slow traffic and cause long tail-backs, slowing people’s journeys even more.
Investigations concluded that the best way to fix problems on this section of motorway would be to make the most of what’s already there, taking a staged approach.
The staged approach
Upgrading the NtAQ section of SH1 is being carried out in stages:
Stage 1 - Improve the SH2 northbound on-ramp (completed in June 2013; watch before and after videos)
Stage 2 - Improve the existing ATMS (underway November 2014 – April 2016)
Stage 3 - Four lane SH1 northbound lane (underway November 2014 – April 2016)
Stage 4 - Four lane SH1 southbound lane. This needs more work into the seismic issues of widening the Thorndon Overbridge, and also depends on duplication of the Terrace Tunnel. This work is not yet programmed.
As well as the four formal stages, some early improvements were done to improve traffic flows at the Ngauranga interchange.
View larger version here [PDF, 156 KB]
Scoping the Ngauranga to Aotea Quay updgrade
The scoping report concluded the best way to solve the problems on the Ngauranga to Aotea Quay section of SH1 is to provide four lanes in each direction and make it a fully-managed motorway. View the report here [PDF, 10 MB]
Ngauranga to Aotea Quay updgrade - scheme assesment
The Scheme assessment report was completed in July 2012. You can find out about the report and read it here. [PDF, 1.5 MB]