One lane of State Highway 2 at Whakaki, north of Wairoa, is now open after a logging truck rolled just after 7am.
The accident happened just after 7am Tuesday at Whakaki, NZ Transport Agency / Waka Kotahi said.
Logs were "strewn across the highway".
Stop/go traffic management is in place with a temporary lower speed in place, while the logs are cleared from the road.
Road users should expect delays while the backlog of traffic is cleared.