There are calls for a levy to be placed on transport companies in order to fund a dedicated Garda unit.
SIPTU says action needs to be taken in order to deal with the increasing number of incidents of anti-social behaviour on trains and buses.
Its transport sector organiser, John Murphy, feels there is a fear among the public and workers who use the services at times.
Mr Murphy said: "Late in the evening and weekends, it is fairly volatile. There is definitely a fear among our members, a fear among the travelling public that they will be isolated.
"There is security provided by transport operators, and while that is, sadly, needed, we think it can be improved upon and we think it would be a bigger deterrent if there was a dedicated Garda Siochana present with the powers of arrest and detention."