The GRS (geo-synthetic reinforced slope) wall in Zone 2. Photo: Waka Kotahi / Supplied
Millions of cubic metres of earth has been dug out, smoothed over and cut through as work on the new highway between Manawatū and Hawke's Bay reaches its halfway stage.
Construction started on the $620 million, 11.5km road, Te Ahu a Turanga Manawatū Tararua Highway, in January 2021. It is due to open in December 2024.
The four-lane road will replace the former State Highway 3 through the Manawatū Gorge, which closed in 2017 due to slips and will not reopen to traffic.
Since then, traffic between Ashhurst and Woodville has taken the windy Saddle Rd, which has a 60km/h speed limit.
In December 2022, Waka Kotahi posted a flyover video of the progress that had been made on Te Ahu a Turanga flyover.
Project alliance owner interface manager Grant Kauri said by the Christmas shutdown, 4.5 million cubic metres of earthworks had been completed, out of a total of 6m.
"We're looking to have the majority of the earthworks substantially completed this construction season," he said. "That's a huge milestone for us and quite a focus."
Construction seasons take place over summer, before wet winter weather begins. And the new road could start to really take shape soon.
"We're also looking to bring our pavement construction online [this] year as well - make some really good inroads there," Kauri said.
The project has faced challenges because of Covid-19 and the terrain.
"We've lost probably around 2800 hours due to how we managed isolation and things like that," he said.
"That's been quite a challenge for us and put a bit of pressure on our workforce.
"In terms of the structures, we did encounter some poor ground conditions on both of our structures."
These are a pair of 300m-long bridges at the Ashhurst end of the road - the Parahaki Bridge over the Manawatū River - and a viaduct over sensitive environmental land.
Pier 1 on Parahaki Bridge Waka Kotahi. Photo: Waka Kotahi / Supplied
Eleven of the 12 columns on the viaduct have been poured. It earlier faced problems because of artesian groundwater at the site, which flowed at a level project staff had not seen before, but Kauri said this had been overcome.
"With the Parahaki Bridge, we've got one of our piers built and the other two, which are starting to show some real good progress."
Kauri said the project alliance - made up of Waka Kotahi, construction and design companies and iwi - would this year assess the construction's progress against the December 2024 expected completion date.
Work on roundabouts at each end of the new road was also underway.
Kauri said about 300 to 350 people were working on the project site.