SH58 Safety Improvements Project Update

31 October 2025

 In this issue

• November road works and road closures 

• Behind the scenes with our construction crews

• Rock solid - building better with Flightys rock

• Base layers - getting the foundations right

• Want to connect with the project team?

Welcome to this update. Here’s an overview of what’s happening now and over the next few months.

The pace of work has really ramped up in the last few weeks. Within the site, you’ll see that every few hundred metres, there’s something going on. 

This multitude of tasks are a visible demonstration of all work that’s been put in by specialist engineering, design and planning experts, and valuable input we received from the local community.

And please remember – as you’re driving along the highway, you’re always welcome to give our crews a wave and smile – they do appreciate your acknowledgement and attention while working in this busy environment.

A 40-tonne digger uses a giant claw to tackle the Flightys rock.

Chipsealing work in November

Resealing from Murphys/Flightys to Transmission Gully

We’re planning to reseal the section of road between Flightys Road/Murphys Road and the Transmission Gully interchange with chipseal, over two to three nights in November.

Weather permitting, this is planned to begin on  Sunday night, 9 November. 

Resealing work needs to be done when it’s relatively dry and when the air temperature is at least 10°C.

Immediately after chipseal is laid, it needs to settle for a few days. A first sweep of the new surface is done to make sure it's all spread out properly and to remove any excess.  We may have to do a second sweep later on.

For two to three weeks after sealing, the speed limit needs to be lowered to 30km/h to allow the chipseal to properly bed in.

You can help ensure the sealing is successful by sticking to the lower speed limit while the surface settles.  This helps the long-term performance of the road and lessens the risk of stone chips from flicking up.

The task is highly weather dependent as there’s no point doing it in bad conditions.

We’ll advise on timings, if things change.


 
 

View from the new Flightys Road diversion looking back at the slowly dwindling Flightys hillock.

SH58 overnight road closure 9-10 November

Wellington Transport Alliance (WTA) will close SH58 Haywards to through traffic to undertake maintenance work from 10pm Sunday 9 November to 4am Monday 10 November.

Residents and businesses will have access to their properties at all times during the closure. All other travellers will have to detour.

Closures allow many jobs to be completed in the most efficient way with the least impact for road users.

WTA's Journey Planner webpage

You can find information about major roadworks planned for the Greater Wellington region - Wellington, Porirua, Kāpiti, Hutt Valley and Wairarapa.

Well-maintained roads are an important part of keeping people safe. While we aim to do this work with as little disruption as possible, we know that roadworks can be inconvenient. Thank you for your patience while we do this important work.

Please drive carefully through work sites and stick to the temporary speed limits. Plan ahead as roadworks on the state highway network may affect your journey times.

Note: Weather or other factors may cause roadworks to be postponed to the next suitable day in our programme.

Behind the scenes with our construction crews

Last month, teams kicked into the drainage with gusto and tonnes of earth has been pegged out, marked with fluro paint, scraped over, dug, moved digger bucket by digger bucket, and compacted back to new levels.

Currently the work is mostly drainage, stormwater installations, and ducting work.  Preparing the ground and building the stormwater lines and swales are among the main tasks being done between now and Christmas.  Drainage work will continue for many months to come.

Currently much of the work centres around drainage, installing stormwater pipes, and preparing for new cabling and ducting pathways.

But it’s not as easy as just digging a straight line and plonking pipes into the ground.  Specialist crews are creating a ‘production of precision’.

Here are some photos from behind the barriers.

Specialist drainage crews create a manhole for Moonshine's roundabout underground drainage system.

The Mooshine site is a scene of foundation first, then building up layer by layer.

PVC pipes ready and waiting to go underground at the Moonshine site.

Rock solid - building with Flightys rock

When you’ve got big earthworks such as cut and fill operations jobs to do, it’s time to call in the heavy hitters in digger power.

People will have seen the 40-tonne and 20-tonne diggers at the Flightys Road hillock, and the specialist operator carefully cutting down the mound. The material is being transported and placed into both roundabout build ups.

Digging down and moving tonnes of earth at the Moonshine site has been required to prepare the new roundabout base and alignment.  Filling the base with quality material that will withstand the demands of a high-traffic volume highway is a mini project, in itself. 

Locals will remember that the previous nearby paddocks’ layer was set down from the existing road by almost two metres. Downer crews had to dig nearly another metre further in places where the base ground material wasn't suitable, to get to a good base layer.

To date, the work done here has involved digging down to good ground and testing at every step. Big rocks are being placed on the bottom layer.  The suitable fill material, transported from the Flightys hillock, has been delivered truck trailer after trailer.  

Other imported material will need to be used as needed because the fill’s quality has to meet strict grade rules and specifications.

Essentially, the inferior earth was removed and is now being back filled it the good-grade Flightys hill rock.
 

Base layers - getting the foundations right

Teams have to be careful to measure and place any new service areas which will be formed underneath the roundabout.

New service alignments need to be factored-in now because they’re shaped, cast and encased in this layer while the roundabout forms from the bottom up.

The most obvious work horses on site are the trucks and diggers. At Moonshine, the diggers can transform themselves with different attachments – from claws to scrape into rock faces, digger buckets to move earth, or they can use their gigantic arms as cranes.

Other machines have roller smooth drums for compacting earth, or another type called a ‘sheep's foot’ roller.

Such rollers have dull spikes that are used to compact new earth fill by kneading it together under pressure.  This achieves a slightly deeper compaction with the bigger stones we’re getting from Flightys hill.

The compaction work involves testing each layer’s density at every 200 to 300mm to ensure resilience and strength, before proceeding with the next level.

Engineers sometimes test with a nuclear densometer machine (NDM), which is a scanning gauge that identifies the moisture, density and make up of materials or surfaces.

NDMs are used in civil construction, geotechnical engineering, the petroleum industry, mining, and even archaeology. In our case, we’re using them to determine the density and moisture of every build layer of the sub-base to ensure a strong road surface.

The NDM emits a signal that’s reflected back by the paving layer. The device can only be used by someone with a nationally-recognised qualification in materials testing, who is also is trained both in the operation and safe practise of using the equipment.

It travels in a special box, away from the operator, with an ‘ionising material’ sign on the vehicle.

Sheep’s foot roller used to knead and compact the larger fill, from Flightys hillock.

Want to connect with the project team?

If you have any questions about the project work, email: 

sh58safety@nzta.govt.nz;

and keep a watch on the SH58 Project webpage:
https://www.nzta.govt.nz/projects/sh58-safety-improvements  

Just a note, if you ever need to report an emergency, incident or have an immediate concern about any highway in New Zealand, call the freephone 0800 4 HIGHWAYS or 0800 44 44 49.

Calls are handled by our national call centre and is staffed 24/7 – every day of the year.