A section of State Highway 2 has been closed after a man was found injured near Greytown, Wairarapa.
Police were called to the highway at around 7am on Sunday and found the injured man, who was airlifted to hospital in a critical condition.
State Highway 2 between North Street and Ahikōuka Road was closed while emergency services attended the incident.
The road was expected to be closed for several hours.
Police said enquiries to establish how the man was injured were ongoing.
Motorists have been advised to avoid the area and follow diversions.