The head of the National Transport Authority (NTA) says she does not believe a dedicated transport police force would be appropriate for Irish Rail.
Anne Graham was speaking as the NBRU is balloting its members for industrial action in protest at the "lack of protection" offered to staff across the network.
The union says anti-social behaviour and "downright thuggery" has gone "well beyond tipping point".
Iarnród Éireann staff are facing threats of violence, sexual assault and open drug use on an almost daily basis, according to the union.
Ms Graham told The Hard Shoulder they are increasing security in a number of ways.
"I know that Iarnród Éireann have been working extensively with their employers, and the trade unions and An Garda Síocahána - as well as with their private security personnel - to ensure that they pro-actively put in place measures to address anti-social behaviour.
"So there's a number of things that they have been working on".
She says this includes a security coordination centre and additional CCTV resources across services.
Asked if transport police would be the answer, she says they would rather work with Gardaí within the existing framework.
"We don't believe that that's appropriate; and I know An Garda Síochána themselves believe that working closely with the operators is the best approach, not to have a specific transport police.
"If you think about a public transport system and you think about trying to provide additional security on those, the first option is to see can you provide that yourself.
"And if there's additional anti-social behaviour, there's very strong links with An Garda Síochána who can respond quickly to events is the best approach - we believe - with Iarnród Éireann to approach those anti-social behaviour [sic]".
NBRU General-Secretary Dermot O'Leary earlier told Newstalk Irish Rail staff have "reached the end of their tethers” after years of anti-social behaviour.
"There is anti-social behaviour on some lines that would be classed in some quarters as low grade – stone-throwing, graffiti and just boisterous general unruly behaviour in stations. That is a concern in itself", he said.
"But certainly, in terms of the more serious stuff that is out there... threats of sexual assault - significantly on a number of women who work in those roles - drunken behaviour, threats and physical violence.
"Some people don’t work on trains anymore as a result of some of the stuff that has been going on."
'Garda transport division'
While last week, Independent Dublin Councillor Deirdre Donnelly told Newstalk a Garda division should take responsibility for safety on public transport.
"We would need to have a designated police service for this. I know at the moment that there would be some difficulties in relation to the legalities of it" Councillor Donnelly said.
"At the moment, the private companies who run and look after the Luas - in particular - the people who are employed by Iarnród Éireann for the DART, those people do not necessarily have the powers to arrest someone, bring them to a Garda station, charge them and all of that.
"In the long-term we could look at a designated Transport Police service.
"But I think in the medium-term, we could certainly look at a division of the Gardaí - for example we have the Traffic Corps, we have a Community Policing division, we have a division of the Gardaí tackling gangland crime.
"And I don't see why we would not have a division of An Garda Síochána there patrolling our public transport to make it safe for everybody".