Today's operation will be the first of a series.
As many as 50 members of An Garda Síochána will be present across Luas, DART and commuter trains from 3pm on Friday (13 September) for the remainder of the evening.
The operation is part of what is expected to be a series of ventures, designed to "support transport operators in ensuring a safe and secure travelling environment for customers," according to An Garda Síochána.
Last year, National Bus and Rail Union General Secretary Dermot O'Leary called for more security on public transport, even putting forward the idea of a specific Garda division to tackle crime on rail and tram services.
As recently as last week, the union had said Bus Éireann drivers could not engage in loading and unloading buses after 8pm for fear of attack. The union has also called on an "assault pay" scheme to be introduced. Bus Éireann is not part of today's scheme.
Garda Superintendent Kevin Daly said of today's operation: "This national initiative will facilitate high visibility policing and positive public engagement aimed at achieving our mission of 'Keeping People Safe.'"
Billy Gilpin, Director of Train Operations at Iarnród Éireann, said: "We very much welcome this initiative and the significant resources being provided."
Also, throughout the evening, there will be Garda community engagement stands at Intercity stations including Dublin (Connolly and Heuston), Cork, Waterford, Wexford, Limerick, Galway, Westport, Dundalk, Tralee and Sligo.
