Ngauranga to Aotea Quay
Building New Zealand’s first Smart Motorway
Slowing down to get there faster might seem like a contradiction in terms, but drivers on Wellington’s new smart motorway are learning that taking their foot off the accelerator makes for a smoother, faster commute.
The section of SH1 between Ngauranga and the Terrace Tunnel is one of the region’s busiest sections of motorway, used by over 90,000 vehicles per day. Growing congestion on the network was causing significant delays and low journey time predictability, and the road had a poor safety record. With no space to build additional lanes, the NZ Transport Agency opted for a managed motorway system to influence traffic flows and help the road operate more efficiently.
The smart motorway uses Intelligent Transport Solutions (ITS) to monitor and respond to changing road conditions, adjusting the speed limit to pace traffic and restrict queue formation. Common overseas (London’s M25 is a famous example), managed motorway systems improve safety, increase journey predictability and even reduce carbon emissions. Ngauranga to Aotea Quay is New Zealand’s first smart motorway but, with growing congestion in many of our urban centres, we’re likely to see more managed motorway systems in the future.
We had to continually stretch our thinking to keep construction – and drivers – moving.
Set in a heavy traffic environment, with works in the central median and on the motorway itself, we had to continually stretch our thinking to keep construction – and drivers – moving. The Roads of National Significance project involved a sizeable construction programme alongside the installation of smart motorway equipment:
- Construction of an extra (fourth) northbound lane between the Aotea on-ramp and the Ngauranga Gorge / State Highway 2 diverge
- Replacement of three kilometres of central median safety barrier with a continuous concrete barrier by Seovic
- Extending the existing sign gantries and adding a number of new ones, and
- Construction of a new southbound on-ramp for emergency services at Ngauranga.