Work is about to start north of the Johnstones Hill tunnels to connect State Highway 1 to the new Ara Tuhono – Puhoi to Warkworth motorway. The northbound lane of Hibiscus Coast Highway is on the right.

The NZ Transport Agency advises that work is about to start on significant road layout changes on State Highway 1 (SH1) at the Johnstones Hill tunnels, north of Auckland.

The changes are part of a staged sequence of work to connect SH1 to the new Ara Tuhono – Puhoi to Warkworth motorway that is under construction north of the Johnstones Hill tunnels. There will be changes to the alignment of SH1 and new lanes added north of the tunnels before the motorway is due to open in May 2022.

“This is an exciting stage of the project because it‘s bringing together the current SH1 with the new motorway and will help fix a known summertime traffic bottleneck at the tunnels for northbound traffic,” says NZTA acting senior manager project delivery Rod James.

The work starting on Sunday 20 September will make temporary lane closures and road layout changes on the Puhoi side of the tunnels. This is to create protected space for the construction team to start widening SH1 lanes coming out of the northbound tunnel.

From Sunday 20 September to Thursday 1 October (not including Friday and Saturday) the northbound tunnel will be closed at night. All northbound SH1 traffic will be moved to a southbound tunnel lane with stop/go traffic management in place.

The Hibiscus Coast Highway northbound lane will also be closed, with traffic diverted onto the southbound lane under stop/go traffic management.

Stop/go traffic management will be in place from 8pm to 5am.

The safety of all road users is the NZTA‘s highest priority and the speed limit in the area will be reduced to 60kph, says James.

“We ask drivers to slow down, take care, watch your following distance with other vehicles and don‘t be distracted by construction activity and workers on the roadside. We want everyone to get home safely.”

On the night of Wednesday 30 September, both northbound and southbound tunnels will be closed for maintenance. This is part of regular maintenance to ensure the Auckland motorway network is kept in a good and safe condition for all road users.

The tunnels will be closed from 8pm to 5am with traffic diverted to the Hibiscus Coast Highway. This effectively closes the motorway toll road between the Silverdale interchange and Puhoi. The detour will be Hibiscus Coast Highway and motorists are advised to allow an extra 15 minutes for the journey.

“Motorists are encouraged to plan ahead, allow extra time for their journey. The night closures are to minimise disruption when traffic is light.  We appreciate your cooperation and apologise for any inconvenience.”

The new Ara Tuhono – Puhoi to Warkworth motorway will extend the four-lane Northern Motorway (SH1) 18.5km from the Johnstones Hill tunnels to just north of Warkworth. It will vastly improve the safety, connectivity and resilience of the transport network between Northland and Auckland, helping to boost the economic potential of the Northland region.