Most earthworks for Manawatū – Hawke’s Bay Highway completed

Major earthworks are complete and pavement will soon be laid on a vital transport link between Manawatū and Hawke’s Bay, due to open in about a year.

It has been seven years since the old State Highway 3 through the Manawatū Gorge was closed due to slips, sending traffic onto narrow, winding alternative routes.

The $620 million highway to be built in its place has changed the face of the lower reaches of the Ruahine Range as it climbs hills and winds past wind turbines between Ashhurst, on the north side of Palmerston, and Woodville .

And although the main earthworks have now been completed, the new route remains a hive of activity as heavy machinery works the terrain into a smooth surface ready for motorists.

The new SH3 – this section is called Te Ahu a Turanga – is 11.5 kilometers long. There are two lanes in each direction along the entire route, with traffic separated by a cable barrier, except on two bridges, where there are concrete dividers.

A shared walking and biking trail runs alongside the road.

“We have completed the large earthworks. We have moved 6.5 million cubic meters of earth. This can fill Eden Park more than five times, that is, a quite impressive volume,” said project spokesman Grant Kauri.

“We have minor modifications and things like that, which will continue until the main road opens.”

Kauri said it was estimated that between 8,000 and 12,000 vehicles a day would use the new road, including many large trucks carrying goods.

The new route was originally scheduled to open later this year, but was delayed by Covid, although Kauri could not yet give an exact date.

But the goal was mid-2025, as long as the climate behaved. And this summer it did, after a wet 2022-23, including Cyclone Gabrielle, where the flooding of the Manawatū River caused damage.

Another objective was the budget of 620 million dollars.

“That is still our current budget, but with a project like ours (there is) Covid, but also an escalation. That has affected the industry and we are not immune to those costs, so it is something that is under review at this time. moment”.

The road was a wide construction with panoramic views across Manawatū to the coast and the Tararua district around and beyond Woodville. Just for the top layer of asphalt and concrete, 110,000 tons of material were needed.

“We’re actually doing some testing with our asphalt right now… taking advantage of the good weather we have available,” Kauri said.

Problems plagued Transmission Gully and Kāpiti Expressway when they opened in the Wellington region; both needed resurfacing work within months.

Kauri said testing at Te Ahu a Turanga would ensure a suitable surface was found.

“We had a series of test tests that are being done, so all of that work supports the structural integrity of that pavement, to ensure that we are building that resilient pavement.”

At the end of the road in Ashhurst, just about 15 minutes from Palmerston North, two 300 meter bridges will welcome motorists onto the road, before a steep climb.

Kauri said that in a 3-kilometre stretch, traffic would face a 10 per cent gradient.

“It’s pretty comparable to Transmission Gully. It’ll be a little bit steeper on the Ashhurst side, but on the Woodville side it’ll be about 8 per cent, which is a little bit gentler gradient than that.”

The two bridges are among the last parts of the highway to finish construction: one, a viaduct over a sensitive wetland, will be built later this year, and the other, the Parahaki Bridge over the Manawatū River, in a couple of months. after.

Kauri said the challenges faced by the alliance that built the road, made up of Waka Kotahi NZ Transport Agency and contractors, during the Covid-19 period was one of their proudest achievements, as was seeing the new route now as a recognizable highway.

“I look at where construction was in January 2021 when we started, and I see a complete alignment come to life and drive this alignment into construction. It’s a pinch myself moment.”

Between 300 and 350 people worked on the site; In total, about 2,000 people had worked there. Kauri said they had put in more than 2 million hours.

It will take cars about 13 minutes to travel the new road, about half the time it takes now.