Coasties should prepare for State Highway 1 (SH1) closures between Silverdale and Warkworth, as maintenance work is set to begin on Sunday, 15 September.

The NZ Transport Agency (NZTA) advises that the closures will affect traffic in both directions and may cause delays.

Johnstone Hill Tunnels

From Sunday, 15 September to Thursday, 19 September, the Johnstone Hill Tunnels will experience one-way closures nightly from 9 pm to 5 am.

Northbound traffic will be closed from Sunday to Wednesday, while southbound traffic will be closed on Wednesday and Thursday.

During the closures, northbound traffic will use one of the southbound lanes.

Silverdale to Warkworth (17 September)

On Tuesday, 17 September, a full northbound closure will take place between Silverdale and Warkworth, with several ramps closed, including the Silverdale northbound on-ramp and the Orewa northbound off-ramp.

Detours will be in place via Hibiscus Coast Highway and Old SH1.

Warkworth to Silverdale (18 September)

The southbound route will be fully closed on Wednesday, 18 September, affecting ramps from Warkworth to Silverdale.

Drivers are advised to use the same detour routes.

NZTA reminds the public that the work is weather dependent and to check for updates on the NZTA Journey Planner.

Increased noise levels are expected during the maintenance.