A Hato Hone St John spokesman said it sent one helicopter and two ambulances to the incident.
They took one patient with serious injuries to Dunedin hospital, the spokesman said.
Chief Fire Officer Robbie Phillip, of Milton Fire Station, said the station sent a truck and a rescue tender.
Using cutting equipment, they worked with police to help extricate the driver, CFO Phillip said.
The road was closed at Waihola to the north and Milburn to the south, between Limeworks Rd and Phosphate Rd for most of the day.
Police said the road reopened about 6.25pm.
The detour was not suitable for heavy vehicles, Waka Kotahi advised.