Motorists are being treated to the first glimpses of the highway extension replacing the narrow, windy and dangerous section of State Highway 1 between Puhoi and Warkworth.
A row of giant concrete supports along the 18.5km route of the $710 million road greet motorists at Okahu Inlet, just north of the Johnstones Hill Tunnels, where hundreds of native snails were collected and moved away from the construction site.
Towering skywards are two giant cranes, including one crane capable of lifting 600 tonnes and thousands of configurations, nicknamed T-Rex. The cranes are working in tandem to lift steel girders between the supports for a June completion.
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A couple of kilometres up the road at the Puhoi turn-off supports for a second bridge are rising from the ground as the project passes the halfway mark.
The first of seven bridges at Moir Hill Rd, which crosses the new highway south of Warkworth, is due to open before Christmas and be handed over to Auckland Transport.
Project manager Robert Jones says the new highway will be at another level to the spectacular drive along the Northern Gateway between Orewa and Puhoi, which opened in 2009. He oversaw that project and was lured out of retirement to manage the next leg of four-lane highway to Warkworth.
This summer, he says, motorists will come through the tunnel and see the bridge structures with beams on and as they move north of the Mahurangi West turn-off, a lot of earthworks. At the northern end, outside Warkworth, where the highway ties in with a new roundabout at SH1, construction works will come into view. There are no plans to disrupt traffic during the holidays.
When the highway is completed in October 2021, the scenic drive to just north of Warkworth will feature natural forms, a kauri reserve at bridge level looking down on the Puhoi River, 50m-high cut slopes with layers of rock forms breaking out to valley views - all following a curved pathway.
It will be dramatic, says Steve Mutton, who is managing the Kaikoura earthquake work for the NZ Transport Agency while looking after projects in Auckland and Northland.
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Mutton says there has been a significant shift to the way highways are now built compared with the past.
They have to care for communities in the cities, feel safe, look good and showcase the country's spectacular scenery. They also have to care for the environment, be sustainable, represent value for money and, in this case, support population growth and the economy of Northland, he says.
"This highway delivers on all those aspects and is going to improve the safety performance of this part of the network. Between Auckland and Whāngārei there have been significant safety issues," says Mutton.
This is the third, and final, season of cutting seven million cubic metres of earth and rock through the route and filling another five million cubic metres to level the valley floors for a relatively flat road surface.
The summer months offer a window of 120 days to carry out earthworks on the Road of National Significance, officially named Ara Tūhono, and being built by the Northern Express Group (NX2).
This is a joint venture between Fletchers and Spanish construction firm Acciona, on behalf of the NZ Transport Agency. NX2 will operate and maintain the highway for 25 years under a public-private partnership (PPP). After 25 years, the highway will be handed over to the NZ Transport Agency.
Jones lists three goals for this summer - moving the final three million cubic metres of earth, get to the point where seven bridges along the route can be crossed, and begin surfacing the road with a low-noise, porous asphalt surface, which allows water to escape and avoids wheel-spray. This work will take 12 months.
At the peak, 750 people will be working on site and nearly 7km of culvert pipes will be installed by March next year. In the past year, an estimated $25m to $30m has been spent locally from buying coffees to hiring local contractors.
The highway was consented in 2014 with flexible environmental and design thresholds. Work started on the highway, which runs west of the existing SH1, in December 2016. By 2026, it is projected the new road and the existing SH1 route will cater for 35,000 vehicles a day.
The new road, derided by critics as a "holiday highway" for Aucklanders driving to beach homes at Omaha, is seen by the transport agency and others as a better and safer access through to Warkworth and further north.
Separate to the highway project, Auckland Transport is tackling Warkworth's notorious Hill St intersection by building a new four-lane Matakana Link Rd. This replaces an earlier plan to do it in two stages with two lanes at the outset and four lanes as traffic demand grows.
The road is due for completion at about the same time as the new Puhoi to Warkworth highway in 2021.
Both projects will bring huge benefits to the town and surrounding area, which is forecast to grow from a population of 4500 to more than 25,000 and thousands of new businesses over the next 25 years.
Puhoi to Warkworth motorway project - by numbers
$710m - cost
18.5km - length
4 - number of lanes
7- number of new bridges
7m cu m - amount of rock and soil to be cut
7km - culvert pipe system
750 plus - number of workers at the peak
35,000 - number of vehicles per day on new motorway and existing SH1 route by 2026
October 2021- opens to traffic