Motorists are advised to avoid SH1 at Tamahere due to a crash.
Several serious falls in the Waikato area left five people wounded overnight and closed the main road to Hamilton.
Part of the Waikato highway between Hamilton and Cambridge was closed after a freight wagon and a truck arrived in Tamaher on Wednesday at 6.45am.
It happened shortly after another serious accident left two people wounded at a junction south of Templeview.
Shortly after the crash police chief Sergeant Waikato police Jason McKay said the highway would be closed for some time because it seemed to be serious injuries.
St. Jana later confirmed that two people were in critical condition admitted to the Waikato hospital.
The collision happened on Hamilton's side, which led to Hamilton Airport near Bollard Rd.
The police stopped the road and the branches were in place at the Tamahere Interchange and the Hillcrest Junction.
Motorists were encouraged to avoid this area and expected delays.
The serious Crash unit was in place.
Meanwhile, two people were seriously wounded in the second collision in Collins Rd and Tuhikaramea Rd south of Templeview on Wednesday morning.
In the vicinity of the crash there was a heavy mist around Friday, said senior sergeant Simon Cherry.
One person was imprisoned in the vehicle and then released before being taken to a waiting ambulance.
The person was in serious condition and was admitted to the Waikato hospital, a spokeswoman said.
One another is seen as a minor injury was also admitted to the hospital for consideration.
Firemen from Hamilton and Chartwell were on stage at 6.30 am, which provided protection for the scene for the police.
It was the second crash of the night after a truck and a carriage of tomato loads crashed at Pirongia.
The vehicle ended on its side and unloaded the Ormsby Rd power lines just after midnight, Fire and Emergency said North Communications Manager Craig Dally.
The driver was not imprisoned, but allegedly suffered serious injuries and was taken to Waikato Hospital.
The crews from Hamilton, Pirongia and Te Awamut attended.