The fire on Wairiri Road is partially blocking the highway between Glentunnel and Windwhistle, and Fire and Emergency New Zealand crews are at the scene.

An NZTA spokesman said motorists should expect delays through the area.

“People are asked to take care and to expect delays travelling through this area,” the spokesman said.

Traffic management is expected to remain in place for a couple of hours, with updates to be provided as the situation changes.