The General Secretary of the National Bus and Rail Workers Union has called for a dedicated public transport policing unit following a number of serious incidents in recent days.
General Secretary Dermot O'Leary said the drivers involved were shocked but are "doing okay".
Speaking to RTÉ's Morning Ireland, he said drivers took the decision themselves not to work on the route in question, adding that their safety, and the safety of the public, is paramount.
"We've been campaigning for many years...talking about a dedicated garda transport unit. It won't solve every single problem we have with antisocial but it will serve as deterrent and will tell people that are inclined to offend that there's actually a sanction at the end of this, you could be arrested and detained and brought to court," he said.
"We've been speaking to political parties across the whole spectrum and over recent times we are somewhat encouraged that practically all parties now support the view that there should be a policing resource on public transport.
"In recent months the Tánaiste at his own party conference gave support to it, as have Sinn Féin and many others across the political spectrum.
"We're saying it's about time you turned those words into actions and actually create that unit."
Mr O'Leary said both garda representative bodies, the AGSI and the GRA, are "fully supportive" of a dedicated public transport unit.
He said that while such a unit would not "cure all the problems" of antisocial behaviour, it would serve as a deterrent.
