Face coverings must be worn on all buses, planes, taxis and rideshares from next week when the country is at alert level 2 or higher.
Jared Abbott from First Union, which represents bus drivers, said drivers copped a lot of abuse during lockdown trying to enforce social distancing rules.
He said it could get worse if they were forced to check the mask-wearing.
The union wants the government to supply security guards to enforce the rules and keep drivers safe.
"Bus drivers can't just step out of their office, they're stuck in there for six hours at a time so it is really important for them that that working environment is as safe as it possibly can be."
Some taxi drivers are also worried about having to confront drunk, belligerent people who jump into their cabs without a mask.
Wellington cab driver Yena says many riders who have had a few too many drinks would not comply with the new rules.
In the streets of the capital, Emily was one of a number of people who said the move to make masks mandatory on public transport was long overdue.
"It should have been done a long time ago.
"I think it should be mandatory in more places [like] supermarkets, shops - anywhere you're inside with strangers."
Down the road on Willis Street, Kate said wearing a mask could be unpleasant but it was worth it to ensure people remained healthy.
"As a glasses wearer, it is actually pretty hard because they fog up really badly.
"I'm trying to find a hack for that but I'm happy to have that inconvenience if it means that people are kept safe."
The National Party backs the government's decision to enforce wearing masks.
Its health spokesperson Shane Reti said the scientific advice about mask use and public sentiment towards it had evolved during the pandemic.
"If we recall three months ago it wasn't a policy here in New Zealand, nor was it with the WHO [World Health Organisation] which is where we tend to get our advice from.
"So as we've learnt more and as that advice has changed so our policies have changed and we're supportive of the public advice."
Prime Minister Jacinda Ardern said there were no plans at this stage to make wearing a mask mandatory in bars and restaurants.
Most children would also not be required to wear them on public transport, with Health Minister Chris Hipkins saying officials were still working on an exact age and he would have more to say on Thursday.
But for now, he said there was no evidence there was much benefit to make all students wear masks at school.
The regulations allow various types of mask to be used. A bandana, scarf or t-shirt can suffice, and people are being encouraged to make their own face coverings at home.
The rush to craft reusable ones has led to reports of a widespread elastic shortage. Hamilton fabric stop David's Emporium manager Kim Owen said demand had gone up since the new cluster of cases in the community in Auckland.
"We [ran] out of our first lot [of elastic] within probably a week and we had to have some airfreighted in from China.
"We are selling hundreds of metres a day, it is insane."
For those who could not get their hands on elastic, she said: "You can use bias binding if you want to tie it behind your head, you can use ribbon.
"You can strip cotton lycra - and you can put it into thin strips and give it a good pull so it rolls and it is a softer tie to go behind the ears."
While masks can help, the core government advice is still to keep washing your hands and keep your distance.
