Serious injuries to a woman and a two-year-old child have prompted a travel warning for motorists travelling to or around State Highway 25 in the Coromandel.
A single vehicle crash about 10 minutes north of Tairua, on the Whitianga Road, has closed the road down to one lane.
Police are warning motorists not to use the road until at least 8pm or hold off until tomorrow if possible.
Police Waikato communications manager Andrew McAlley said emergency services were still awaiting the arrival of a recovery truck travelling from Hamilton.
Traffic was being diverted on to alternative route, the gravel Tapu-Coroglen Rd, which was "very, very user-unfriendly'', he said.
"It's not very pretty, particularly if you've got kids in the car.''
Officer in charge of the Police's Summer Policing operation in Whangamata, Senior Sergeant Freda Grace, said traffic throughout the eastern Coromandel slowed to a crawl following the crash, which happened shortly before 1pm.
"The crash involved a single people-mover type vehicle travelling towards Whitianga and is still under investigation by the Serious Crash Unit however initial indications are speed was contributing factor.
"The driver of the vehicle appears to have failed to negotiate a sign-posted 25km/h corner, crossed the centreline and gone down a 20m bank.
"The six injured occupants of a variety of injuries and members of the public had to travel from the scene to raise the alarm due to poor cell-phone coverage.''
Ms Grace said the six occupants of the vehicle suffered a variety of injuries with two people, a woman and a two year-old child being flown by air ambulance to hospital with serious injuries.
"The other four occupants were taken to hospital by ambulances that arrived from Whitianga and Hahei.''
Ms Grace said despite the fine weather there had been seven crashes across the Waikato Police District with three happening in the Coromandel placing pressure on responding emergency services.
"While police are working full-time our sister ambulance and fire crews rely heavily on volunteers who are also trying to enjoy their summer holidays.
"With thousands more vehicles on the narrow Coromandel roads over the next few days it's crucial drivers pay attention and slow down. By showing a bit of patience we will ensure everyone gets to and from their destination safely.''
Police are continuing to maintain their zero tolerance approach to any motorists found driving in excess of any posted speed limit over the summer.