The Thames Coromandel District Council asked drivers using the road to allow extra time and be patient. Heavy traffic was expected on the east coast as people headed home from holiday destinations.
The state highway has been closed from Thames to Manaia due to slips, rock falls and dangerous conditions brought about by a monster storm that ripped across the country late last week.
The first big storm of the year had New Zealand in its grip for around two days late last week, with heavy rain and gale-force winds battering the central and lower North Island.
The Wellington and Kapiti regions along with the top of the South Island were also hit by the storm, with the wild weather causing surface flooding and huge waves.
A woman was killed in Rotorua on Friday after a tree fell on the car she was in.
Photos showed Thames Coast Rd with large holes bashed into it. Loose chunks of asphalt were flipped over by the waves.
The council said the road had now become a "very long work site" with around 10km of damaged highway.
Maraetai Coast Rd, in southeast Auckland, has re-opened to one lane.
East Coast Rd at Orere Pt remains closed north of Kaiaua through to Kawakawa-Orere Rd due to storm-related damage.
Offers of help were flowing in for those affected by flooding caused by the storm, which took out fences, inundated homes and destroyed people's possessions.
A Facebook page for a community's volunteer fire force in the small east coast town of Kaiaua said a community meeting would be held tomorrow evening to gauge the needs of those affected.
The town was hit hard by waves of seawater which burst over a low bank. Many people had been unable to return home and businesses such as the town's The Pink Shop remained shut.
Residents had also expressed concerns on the page around health and safety with dust being thrown up from the roads on the coast by passing vehicles.
"If you have stuff you would like to donate please contact us further for more info on drop off points etc," it said.