State Highway 2 between Opotiki and Gisborne is closed after a truck overturned.
The driver is uninjured but the road will probably be closed for most of the day, police said.
Heavy lifting equipment is needed to clear the road.
Motorists are being advised to avoid the Matawai area or delay their travel.
The New Zealand Transport Agency advised drivers to take State Highway 35 around the East Cape but warned the detour would take around 4.5 hours instead of the usual two hours on SH2.