A Garda transport hub in Dublin's Heuston Station must be a 'first step' in a wider programme to protect people on public transport, according to the NBRU.
It comes amid plans to station Gardaí in train stations from next month.
The new hub, known as a Command and Control Centre, is set to open at Heuston Station on May 5th.
Officers at the hubs will have oversight of all public transport networks - including trains, buses and trams.
Plans are also being examined to put a similar centre at Connolly Station in the capital.
NBRU Assistant General-Secretary Tom O'Connor told The Pat Kenny Show the plan must be capitalised on.
"Any investment in the provision of security for public transport workers and users is welcome," he said.
"We believe it's only the first step.
"The hub at Heuston, and potentially Conolly, needs to be enhanced upon.
"We've been calling for a dedicated and fully-funded An Garda Síochána transport division for some time.
"That's what is required to police the public transport network - the network is vast.
"While the hub at Heuston [and] a hub at Connolly will enhance the security... to some degree, it's not going to take care of the problem of anti-social behaviour".
'A physical presence'
Mr O'Connor said the money being put into the transport network - such as the investment in Bus Connects and the MetroLink - needs to be matched with investment in security.
"All this money and all this investment is for nothing if we can't convince the workers and the people that still use the private car for journeys to swap on to public transport," he said.
"They'll only do that when public transport is safe".
Mr O'Connor said prevention will only work with an actual Garda presence.
"A physical presence in Garda uniform, or multiple Garda uniforms, will prevent something," he said.
"Having this hub - or even as is currently a direct line to An Garda Síochána - is reactionary.
"So, we're always after the fact; after the assault or after the attack, or after the robbery has taken place, there's intervention.
"What we're calling for is something more, so there's a presence there to prevent these assaults from happening," he added.
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