One motorist, returning with four passengers from the David Tua- Shane Cameron boxing match at Mystery Creek in the Waikato, told NZPA hundreds of cars were trapped on State Highway 5 between Taupo and Napier.
Only four-wheel drives, including fire trucks, were able to move on the blocked roads, and no one knew what was going to happen, he said.
Napier police confirmed motorists were trapped on the road but could not give any further details.
The New Zealand Transport Agency said the road from Napier to Taupo would remain closed overnight, and it was hoped it would reopen tomorrow.
Police central communications Inspector Kirsty Henson said about 120 cars were stuck on State Highway 1 between Waiouru and the Three Sisters.
Police were organising evacuation of the people trapped in the cars and would return them to their vehicles tomorrow, she told NZPA.
Snow had also closed SH49 between Ohakune and Waiouru, and SH47 at Turangi, she said.
The MetService has issued heavy snow warnings for the central North Island high country, from the Tongariro National Park and the hills and ranges of Hawkes Bay.
"Snow is expected down to 400m, with heavy falls through to (tomorrow) morning, especially above 600m," forecaster Andy Downs said.
A heavy rain warning was also in place for the Eastern Bay of Plenty, Gisborne and Hawkes Bay.
East of Whakatane, rain should ease early tomorrow, with 50-70mm of rain expected to fall until then, he said.
Heavy rain was expected in Gisborne until tomorrow morning, easing by evening.
