Cyclone Gabrielle exacerbated slips on State Highway 1 over the Brynderwyns, resulting in road closure for repairs. Photo: NZTA / Waka Kotahi
Trucks with trailers will be banned from one of the detours around the Brynderwyns when the slip-plagued highway between Auckland and Northland closes later this month.
The roughly 10-kilometre stretch of State Highway 1 is set to close for critical repairs from 26 February to 27 March, and again after Easter from 3 April to 12 May.
NZ Transport Agency Waka Kotahi and the Whangārei and Kaipara district councils have spent $5.5 million upgrading the key detour routes to ensure they are as ready as they can be for a significant increase in traffic.
The shortest detour, adding an extra 14km to the trip between Auckland and Whangārei and recommended for light traffic only, will be via Cove Road, through Mangawhai and Waipū on the eastern side of the Brynderwyns.
The detour via Paparoa-Oakleigh Road, to the west of the Brynderwyns, will add 21km.
The heaviest class of trucks, the so-called HPMVs (short for 'high productivity motor vehicles'), will have to use a much longer route around the west coast on State Highways 12 and 14, adding an extra 71km.
A map of the detours around the Brynderwyns which can be used when a 10km stretch of SH1 is closed for critical repairs from 26 February to 27 March and again from 3 April to 12 May. Photo: NZTA / Waka Kotahi
A map of the detours around the Brynderwyns which can be used when a 10km stretch of SH1 is closed for critical repairs from 26 February to 27 March and again from 3 April to 12 May.
Northland Transportation Alliance general manager Calvin Thomas said lessons learned from last summer's unplanned Brynderwyns shut-down would help make the upcoming closure smoother for motorists.
That included clearer signage to prevent drivers getting lost or being sent the wrong way.
Last year chaos ensued after large trucks twice got struck on a hairpin bend on Cove Road, a problem that was solved only when a State of Emergency was declared, allowing Northland Civil Defence to restrict heavy traffic.
This time Thomas said a provision of the Land Transport Act would be used to ban trucks with trailers from Cove Road.
Trucks without trailers would still use Cove Road for local deliveries.
Another problem arose last time when Google Maps directed motorists onto Waipū Gorge Road because that was, on the map at least, the shortest route.
However, Thomas said it was entirely unsuitable as a detour because it was narrow, unsealed and winding.
This time Gorge Road would have traffic management in place to make sure it was used primarily by local residents.
"That's definitely not a route you'd choose as a detour. We'll have active monitoring of Gorge Road to make sure people aren't sent down the garden path," Thomas said.
While Paparoa-Oakleigh Road was recommended for light vehicles, trucks would still be permitted to use it, with the exception of HPMVs.
Locals and travellers would notice an increase in traffic even with the load split over three detour routes.
"The reality is, we're going to have state highway traffic on local roads," Thomas said.
Meanwhile, NZTA Waka Kotahi regional relationships director Steve Mutton called on travellers to use the highway closure as an opportunity to explore some scenic parts of Northland.
That included the many beaches along Cove Road and Matakohe's Kauri Museum, a short distance from Paparoa-Oakleigh Road.
Mutton said work to prepare the detour routes was on schedule for completion ahead of the 26 February closure.
"We recognise these detours will take longer, especially for freight, which is why we will be working as quickly as possible to carry out this important work.
"We encourage people to use it as an opportunity to explore Northland and have an adventure," he said.
Some road works would be carried out at night in the Brynderwyns prior to 26 February, but the highway would remain open under stop/go traffic management.
Initially NZTA Waka Kotahi had planned to carry out the slip repairs over a seven-week period starting on 7 February, but it was postponed after an outcry from Bay of Islands tourism businesses.
