The head of the National Transport Authority (NTA) has said it is "definitely encouraging" the use of face coverings on public transport.
It comes as the country re-opens further under phase two of the easing of restrictions.
It will see Bus Éireann, Dublin Bus and DART services return to a regular Monday to Friday timetable service.
Luas and rural services had not reduced their frequency.
Anne Graham, CEO of the NTA, told Newstalk Breakfast: "Normally I'd be encouraging as many people to get on their public transport system as possible.
"But what we're trying to encourage now is that for those that are working from home, we'd ask them to continue to work from home.
"Because with social distancing, our public transport system - even though we've gone back to Monday to Friday service - is still at 20% of its normal capacity".
"So what we're trying to do is use that capacity as best as possible.
"The priory for peak-time in particular is essential workers".
She said they will be launching an information campaign later this week on the wearing of face coverings.
"We are definitely encouraging the use of face coverings on public transport - really for consideration of other customers as well as the staff.
"I understand that the usage is low, that's why we're having an information campaign commencing this week, which will really drive the message home to encourage as many people as possible to to wear face coverings."
Asked if she would like to see it made compulsory, she said: "I think that's for NPHET and the Government to make that decision - obviously we are obliged to follow the public health guidance.
"It's not mandatory in Ireland, but we're doing all we can in terms of the messaging that we're using to encourage as many people as possible to wear face coverings.
"We think that we will see a change in behaviour over the next few weeks as you see more and more people wearing face coverings".
Health Minister Simon Harris has also appealed to people to wear face masks on public transport, and that the Government has "an open mind" on whether the law needs to change.