Coasties travelling north or south on State Highway 1 (SH1) this month may experience delays as essential maintenance gets underway.

NZ Transport Agency (NZTA) has advised that road improvement works will take place between Silverdale and Warkworth, including the Johnstone Hill Tunnels, starting Sunday 16 March.

The works will include resurfacing, vegetation control, and tunnel maintenance. Scheduled closures and lane restrictions are as follows:

Johnstone Hill Tunnels will be closed to northbound traffic day and night from 21:00 on Sunday 16 March until 05:00 on Friday 21 March.

➔ Traffic will travel north using one of the southbound lanes.

➔ Drivers are asked to slow down and follow instructions.

Silverdale interchange to Warkworth roundabout northbound will be closed 21:00–05:00 on Tuesday 18 March.

➔ Several ramps will also close, including Silverdale northbound on-ramp and Orewa northbound off-ramp.

➔ A detour will be in place via Hibiscus Coast Highway and Old State Highway 1.

Warkworth roundabout to Silverdale interchange southbound will be closed 21:00–05:00 on Wednesday 19 March.

➔ Ramps such as Puhoi southbound on-ramp and Silverdale southbound off-ramp will be closed.

➔ Southbound drivers will detour via Old State Highway 1 and Hibiscus Coast Highway.

Silverdale interchange to Oteha Valley Road southbound will have lane restrictions 21:00–05:00 from Monday 17 to Thursday 20 March.

➔ Southbound lanes remain open, but delays are possible.

These works are weather dependent and may be rescheduled if conditions change.

NZTA encourages drivers to check the NZTA Journey Planner for the latest updates.

If you’re heading north or south during these times, plan ahead. Increased noise and travel delays are expected due to resurfacing, vegetation control, and slip remediation.

Extra caution is urged for those using detours through the Hibiscus Coast Highway and Old SH1.

NZTA apologises for any inconvenience and thanks motorists for their patience as they work to maintain road safety and quality.

Got a local story?

We’d love to hear it! Send your tips to [email protected]