A new Garda transport hub will open at Heuston Station today.
Gardaí will have oversight of all public transport networks, including trains, buses and trams.
National Bus and Rail Workers Union General Secretary Dermot O'Leary says it won't solve the problem of anti-social behaviour.
'Unfortunately, it will not address the core issue which is that people are travelling on trains and on buses and they seem to think they can offend with abandon without a charge or a bus sanction, again we've been calling for this for a long long time, to have that dedicated force there.'