Face masks are currently mandatory on public transport in Wollongong, Greater Sydney and the Blue Mountains - but not all commuters are following the rules.
A number of commuters were seen getting on and off trains in Wollongong on Thursday maskless.
NSW Police Deputy Commissioner Gary Worboys said up to 12pm on Thursday, around 150 cautions had been given to people for not wearing masks on public transport and other places where they should.
Wollongong passengers said they were happy with the rate of mask-wearing on local trains, and were not concerned that some people did not follow the rules.
Representatives from the Transport Workers Union NSW and the Rail Tram and Bus Union NSW said if the NSW government was going to mandate masks on public transport, the government also needed to supply the means to enforce them.
Richard Olsen, from the Transport Workers Union, said bus drivers did not have the capacity to enforce mask wearing.
"We support the wearing of masks and social distancing, but the state government needs to ensure they provide enforcement personnel," he said.
"There have been instances where passengers have declined reasonable requests and our drivers have been verbally abused and we don't want to see those things occurring."
Rail Tram and Bus Union NSW secretary Alex Claassens agreed.
"It's disappointing to hear reports of people ignoring the mandatory mask wearing on public transport," he said.
"Physical distancing isn't always possible on public transport and wearing a mask helps improve safety for commuters, their fellow travellers and our transport workers.
"The RTBU calls on the NSW government to introduce COVID marshals on our trains, buses and trams to help enforce health regulations that keep us all safe."
The restrictions were introduced on Wednesday at 4pm and will last for a week.
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