A Dublin Bus driver has said some stops may not be served at night due to security concerns.
It comes amid issues with passengers being left behind due to a lack of capacity, and worries around anti-social behaviour.
This has led to Dublin Bus writing to the National Transport Authority (NTA) looking for action and extra capacity.
Bus driver Sean Yates told The Pat Kenny Show some areas are becoming problematic.
"It's a bit of a horror story at the moment," he said.
"The drivers are reporting that the capacity issues and the anti-social behaviour issues around key stops in the city centre is becoming really problematic.
"They are fearful that it's going to escalate, with a potential for another Wellington Quay."
Sean said drivers may decide to not service certain stops.
"I know only last week at one of our union meetings the drivers reps from Phibsborough Depot had written to the company to say... that [if] it's not safe they're just not going to stop at the stops".
'Venting their anger'
Sean said the company cannot simply add more capacity.
"Unfortunately - from Dublin Bus' point of view - years ago where they'd be able to just slot a bus in when they wanted, they have to go to the NTA for funding for anything these days".
He said the issue is particularly acute as nightclubs all close at the same time.
"You've a bus coming around with capacity for 90, and there could be 60 people standing at the stop," he said.
"Then there's probably 30 or 40 already on the bus.
"The drivers are frustrated because obviously they just want to load and go.
"They've been venting their anger at the trade unions, and we obviously in turn have had to get on to Dublin Bus and say, 'Look we need capacity issues resolved here' - and also there's an element of security".
Kieran Harte, Head of Ireland for Uber, said taxi numbers have dropped dramatically.
"We have seen a shortage of taxis for a number of years now - we used to be at 27,000 taxis in Ireland, we're now down to 19,000," he said.
"What we need to do is get more taxis, more hackneys on the road and more drivers driving".
Mr Harte said regulation around taxis and hackneys means any new vehicle has to be wheelchair accessible.
Mr Harte said those types of vehicles are simply not available.
"We're not seeing the number of new wheelchair accessible vehicles grow to the point where it is replacing the amount of vehicles that are leaving the industry.
"The single, best thing we can do at the moment to improve access for wheelchair users is actually increase the overall number of taxis and hackneys on the road; so that people who need those wheelchair vehicles aren't competing with the general populous," he added.
Listen back to the full segment below: