A crash is blocking the intersection of State Highway 1 and State Highway 5 in Tirau, police say.
Emergency services are dealing with the accident and are putting diversions in place.
State Highway 1 is blocked in both directions, causing significant traffic delays. Motorists travelling between Putaruru and Tirau are asked to travel via State Highway 5 and State Highway 28, or delay travel until the scene is cleared.
The fire service said a truck and car had collided and one person was injured, but no one was trapped in vehicles.
Fire crews were assisting with traffic control.