UPDATED: State Highway 2, through the Karangahake Gorge, is now open after a crane was brought in to clear an overturned truck from the road.

The 15-tonne truck carrying concrete wall units crashed and rolled on a straight section of road near the Wahi end of the gorge about 5.30am.

A truck has crashed blocking a section of the Karangahake Gorge between Waikino and Paeroa. Photo: Chris Hilcock.

The driver was reportedly moved out of the cab and into an ambulance for treatment, says Northern Fire Communications shift manager Jaron Phillips.

"The crash happened just after 5.30am on a section of windy gorge road between School Rd in the Karangahake township and Waikino.

"Fire crews from Waihi were on site helping to control traffic."

A detour was in place via SH26, SH25A, SH25 back onto SH2.

Meanwhile, on the Coromandel Peninsula overnight the driver of a car refused medical treatment after crashing on Kennedy Bay Rd.

The driver was able to escape the vehicle and was taken to a nearby house, says Jaron.

"Before the ambulance arrived, the patient was taken to a house with cuts to the leg and a sore head."

St John Ambulance paramedics offered help to the driver, who was resisting hospital treatment.

No other vehicles were involved in the crash, which occurred just after 9pm.