State Highway 2 near Katikati has partially reopened after a serious crash this afternoon.
Western Bay of Plenty head of road policing Senior Sergeant Ian Campion said one lane of the road had been reopened.
He said police hoped to open the second lane by 5.15pm.
Traffic was banked up to Bethlehem and Mr Campion said drivers could expect significant delays and were asked to avoid the area, or delay trips until later in the day.
The crash involved two cars and both drivers were trapped, needing to be cut out by the fire service.
Both people were taken to hospital with serious injuries.
The road was completely closed after the crash, which happened about 3.20pm.
The crash occurred near Tetley Road.
A diversion was available through State Highway 29 Kaimai Range, which could add an extra 45 minutes to a normal journey.