O Mahurangi project update

1 May 2025

Click the picture above to watch our latest flyover

April video

Some key highlights over the summer include -

• Placing the beams on the SH1 overbridge
• Starting our landscaping 
• First permanent kerbs place on Duck Creek Road
• The Weiti River Bridge land-based piers (Piers 1 and 2) have reached their final height

Take a look at how the project has progressed with our April flyover. You can watch the video in high definition by increasing the video quality to 1080p or higher under the "settings" button in the bottom right corner. You can also adjust the speed to view at your preferred pace.

SH1 overbridge and the northbound offramp are taking shape

What's happening in May

State Highway 1 and Ara Weiti Road

On the nights of 6 and 7 May there will be a full closure on SH1 between Oteha Valley Road and Silverdale so please plan ahead. During the closure we will be pouring concrete on the deck of the new overbridge.

As you travel along SH1 you may notice our earthworks teams continuing to shape the northbound offramp which will provide access to the new road. 

Works are continuning along Ara Weiti Road with pavement trials, the construction of the MSE walls at Link Road 1 and retaining wall works at Link Road 2.  

Stillwater

From late May there will be an increase in large deliveries as a tower crane is transported to site in sections. The crane will be erected on site and piling will continue for its support base. Please take care if you see one of our pilot vehicles on the road. 

The river-based piers are continuing to grow in height, and the crane on the eastern side of the river will also have its boom extended this month. 

In mid-May there will be a temporary river closure, please see below for more details. 

Whangaparāoa 

Construction of the realigned intersection at Beverley and Whangaparaoa Roads will begin this month. Works will be in a staged approach to keep the existing roads open.

Nightworks will be required on Sunday 11 and Monday 12 May from 8pm to 1am between Beverley Road and 532 Whangaparaoa Road. There will be stop/go along Whangaparaoa Road between Beverley and Brightside Roads, so please plan ahead if travelling along here. 

Earthworks continue along the route towards Weiti River. Drainage and utility works continue and the site team will move into the temporary buildings by Cedar Terrace. The larger house, previously used as a site office, will be transported off site by a truck at night later in May. 

Heavy vehicle crossing, East Coast Road

Recent questions

Why is the route only two lanes?

The new highway will be a two-lane road as our traffic modelling shows this is appropriate for the predicted volumes. The new highway will take traffic off Whangaparāoa Road and the modelling expects it to carry approximately 15,000 vehicles per day in the late 2020s and approximately 20,000 vehicles per day in late 2040.

The entire route, including the Wēiti River Bridge, is wide enough to accommodate four lanes of traffic when the demand is met. The road has been designed for an 80 km/h speed limit and will not include passing lanes. If a vehicle were to break down, there is sufficient width for the broken-down vehicle to move over and allow traffic to pass.

When are you removing the ramp on East Coast Road?

The raised crossing was installed to protect underground services and to allow heavy construction vehicles to cross the road between worksites. The crossing is still used for construction vehicles and will be used to transfer earth later this year.  It will remain in use for the duration of the project.

Since installation there has been an additional safety benefit. Previously we have had near miss incidences with people travelling well in excess of the posted speed limit through our worksite. With 6 Site Access Points in a small vicinity on East Coast Road, this is not an acceptable risk to our workers or the travelling public. 

600 tonne crane

Machinery spotlight -Lattice boom mobile crane

The crane we used to place the beams on the State Highway 1 overbridge is a lattice boom mobile crane. These types of cranes are of the largest in the industry and have high mobility whilst being able to hoist very heavy loads. Boom cranes allow for 360-degree movement, and the lattice part in the name is from the W or V lattice shape which decreases the overall weight of the crane whilst still providing maximum support for the heavy loads it lifts.

At 600 tonnes, this is one of the largest cranes in New Zealand. It allowed the team to place the beams without needing to put cranes and platforms on State Highway 1. This helped to ensure the motorway would open at the planned times and not hinder early morning commuters.

Weiti River Bridge

Upcoming river closure

Over the next three months, the Wēiti River will have short term closures during the week, to ensure safe and continuous supply of concrete for the Pier 4 pile cap.

The first closure is from 5pm Tuesday 13 May to 9am Thursday 15 May, with a back up date of Tuesday 20 May to Thursday 22 May. 

We will provide dates for June and July in upcoming e-news. 

The channel closure does not affect vessels navigating the river downstream of the worksite.When the work is complete, we will reopen to the 18-metre-wide navigable gap for vessels to pass through.

We apologise for any inconvenience caused and thank all river users and neighbours for their patience during the ongoing construction of the new Wēiti River Bridge. Should you have any questions regarding this closure, please don’t hesitate to contact us.

More information

For more information on the O Mahurangi project, contact us at omahurangi@nzta.govt.nz or by calling 0800 7365 465.

Visit our website www.nzta.govt.nz/penlink.