Heavy vehicles under 50 tonnes can travel onto a contentious detour route in Northland, as the road is deemed safe and provides a critical link for essential service delivery to the region.

The Paparoa-Oakleigh Rd that links up with State Highway 12 in Kaipara and SH1 in Whangārei was initially announced as a detour route for light vehicles only, with a 70km/h speed restriction, while heavy vehicles were advised to use SH14 and SH12.

A number of travellers on the Paparoa-Oakleigh Rd have regularly vented their frustration at the sight of fully-laden logging trucks, milk tankers, campervans and stock trucks using the route to get to and from Whangārei.

On Monday, an Advocate reporter counted 21 large trucks while driving the roughly 30km Paparoa-Oakleigh Rd from the turnoff on SH12, just east of Paparoa, to Mangapai Rd.

They included fully-laden logging trucks, truck-and-trailer freight trucks, stock trucks, and heavy trucks carrying building supplies such as cement and lumber.

That number did not include light trucks, but it was not clear whether the heavy trucks were breaching the detour’s load limit.

Northland Transportation Alliance general manager Calvin Thomas said just because a truck displayed an “H” plate did not automatically mean it was over 50 tonnes.

Thomas said the plates generally stayed on the vehicles at all times, even when they were not carrying a load.

He said the use and options for placing any further vehicle restrictions on the Paparoa-Oakleigh Rd were discussed at a multi-agency meeting last weekend.

At that meeting, he said the decision was made to continue with current use, given this was the last remaining viable local road access route that provided a critical link for emergency services and utility vehicles such as milk tankers and supply chain deliveries south of Whangārei.

“This decision was informed by the geotech assessments that identified no significant signs of further deterioration at monitored sites as a result of the recent increased traffic loadings and the speed limit reduction implemented last Friday to improve safety,” Thomas said.

He said although SH12 and SH14 were the designated primary heavy vehicle detour routes being actively promoted with transport and freight industries, there were restrictions for heavy vehicles that travelled to Whangārei and further up north.

While the Brynderwyns were fully closed, a heavy goods vehicle needed to do 135km/hr or an additional 74km from Kaiwaka to Whangārei via Dargaville compared to driving over the Brynderwyns.

The Paparoa-Oakleigh Rd is an additional 20km while Cove Rd takes an extra 77km.

Waipū Gorge Rd is currently closed due to slips.

On the enforcement of weight restrictions along Paparoa-Oakleigh Rd, Thomas said he was aware police have increased the frequency of patrols along this route.

Police confirmed no infringement notices for overweight vehicles had been issued by midday yesterday.

The Kaiwaka-Mangawhai Rd and Cove Rd are expected to reopen for light vehicles before this weekend while Waipū Gorge Rd remains closed due to multiple slips, although there is a passable “drive with caution” sign for locals.

Waka Kotahi NZ Transport Agency opened the northbound land on the Brynderwyns from 8am today.

“Confirmed timeframes for full reopening of this route in both directions is still being determined – most recent communications released by Waka Kotahi were indicating/targeting late March,” Thomas said.

He said while the temporary roading arrangements were not ideal, however, given the unprecedented level of damage incurred on state highways, local roads and the rail network, they provided a critical but fragile freight supply chain connection between Auckland and all of Northland.