NZ Transport Agency Waka Kotahi (NZTA) is advising motorists of a full closure to both northbound and southbound traffic on State Highway 1 between Silverdale and Warkworth from 9pm on Monday 21 October to 3am on Tuesday 22 October.

Waka Kotahi will be working with Fire and Emergency NZ (FENZ) and NZ Police to stage an emergency exercise in the Johnstones Hill Tunnel during this time.

Light vehicles will be detoured via Hibiscus Coast Road and Old State Highway 1. 

Overweight vehicles will not be able to use Grand Drive in Orewa due to weight restrictions. 

These emergency exercises are part of an ongoing programme at both the Johnstones Hill Tunnel, Waterview Tunnel and Victoria Park Tunnel and enable emergency response teams to practice, review and update emergency response protocols.

This closure is weather dependent and may change from advertised dates.

Please take care when travelling through our work sites and watch out for our crews. Reduce your speed, adhere to the temporary speed limits and follow the directions of traffic management staff and signs. 

NZTA thanks everyone in advance for your patience and apologise in advance for any inconvenience this may cause.