First piece of road laid on motorway to Warkworth
When the highway is completed, it should be a spectacular drive
The first piece of road has been laid on the new motorway replacing the narrow, windy and dangerous section of State Highway 1 between Puhoi and Warkworth.
Officially named Ara Tu¯hono, or “connecting path”, the motorway has faced delays and cost overruns from the impact of Covid-19.
The motorway has also been dubbed by critics as a “holiday highway” for Aucklanders driving north to beach homes.
Before Covid hit, the NZ Transport Agency paid a joint venture of Fletcher and Spanish construction firm Acciona $83 million to cover delays at the northern end.
A five-week shutdown at the tailend of the earthmoving season when the sun was shining and the soil was dry cost a further $85m and pushed back the completion date by six months to May 2022. The motorway will now cost $878m, up from the original price of $710m.
NZTA senior project manager Andy Thackwray said the Covid-19 delays meant the contractors were not able to complete the final earthwork season over summer and autumn. “The project is now back up and running at full speed with about 500 staff on site,” he said.
The Puhoi to Warkworth motorway is being built as a publicprivate partnership (PPP) between the Government through NZTA and the Northern Express Group (NX2) — a joint venture between Fletcher and Acciona.
Project director Robert Jones said work is progressing well on two major viaducts just north of the Johnstones Hill tunnel and Puhoi at the southern end of the 18.5km motorway.
Currently, huge concrete girders weighing up to 50 tonnes each are being trucked to site from Napier and lifted onto the Puhoi viaduct using massive crawler cranes.
Four girders are lifted at a time — a total of 200 tonnes. Of the 52 girders, 26 have been installed on the 316m long viaduct, which is up to 21m high.
Jones said the two viaducts and seven bridges were due to be completed by February. Work could then start to connect all sections of the project and pave the road.
Just north of the viaduct, the first piece of road has been laid at a major cut in a hillside..
The first layer of the road consists of 300mm of graded and compacted rock. This will be followed by two layers of asphalt 180mm thick and a third, 50mm layer of porous asphalt.
The final asphalt surface is a lownoise surface, which allows water to escape, avoids wheel-spray and helps run-off. When the highway is completed, said Jones, it would be a spectacular countryside drive.
The drive to Warkworth will pass 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.
Thackwray said the road will chop 11 minutes off the current route and be a safer journey. The motorway was consented in 2014. Work on the motorway, west of the existing SH1, started 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 NZ Transport Agency has proposed a toll on the new motorway of $2.40 for cars and $4.80 for heavy vehicles, which is the same as applies to the existing motorway from Orewa to the Johnstones Hill tunnels.
This will take the cost of motorway driving from Orewa to Warkworth to $4.80 for cars and $9.60 for heavy vehicles.