The speed limit on a section of State Highway 10 near Kerikeri will be dropped from 100km/h to 80km/h in a bid to reduce serious crashes.
The limit on either side of the Kerikeri roundabout is already 80km/h but that will now be extended north by about 2km, to a point 500m north of Waimate North Rd.
The New Zealand Transport Agency, which is responsible for the country's state highways, said increased development in the area had brought more traffic and a corresponding increase in crashes.
Highway manager Brett Gliddon said lowering the speed limit was part of NZTA's commitment to reducing the number of deaths and serious injuries on the roads.
"It recognises that people make mistakes and are vulnerable in a crash, and aims to reduce the price paid for a mistake so crashes don't result in death or serious injuries. This includes building safer roads, and encouraging people to drive their vehicles at safe speeds."