Driver shortages and IT problems have been blamed for "phantom" or "disappearing" buses in Dublin.
The two main bus operators in the capital will go before politicians on Tuesday morning to explain recent issues with services.
Commuters in Dublin have been complaining of increasing problems with real-time passenger information and so-called "phantom" buses leaving people stranded at stops.
Dublin Bus will tell the Oireachtas Transport Committee that it has been working hard to fix software problems that have coincided with serious driver shortages.
It has said there have been software problems which it has “been working hard to fix”. It said those technical issues “unfortunately coincided” with the current driver recruitment shortages.
“This has resulted in the company having to cancel some trips due to [driver shortages]. The cancelled trips should be removed from the real-time system in a timely manner. But in some cases, this was not happening.”
It said a new process was being put in place to address this issue.
In its statement, the company said it managed to operate 97 per cent of all services for the first six months on 2022 within three minutes of scheduled time, short just 1 per cent of the target. However, since the summer, this has fallen to 95 per cent, 3 per cent off target.
Dublin Bus says difficulties in recruiting new staff, particularly drivers, is the main factor behind the decline in operating efficiency.
“The pace of expansion of the network is outstripping the pace of recruitment of new staff, particularly in the driver grade,” it says in a statement to the committee.
The company has recruited an additional 290 drivers in 2022 and has conducted a big recruitment drive. “However, even with this number of new drivers, we are not keeping pace with the rate of network expansion,” according to the statement.
Dublin Bus reports that customer demand had returned to pre-Covid levels and it is carrying 400,000 customers a day, over 7,000 trips.
Go-Ahead, which operates 30 routes in total, also acknowledged there have been “issues related to our services”.
It also said it had been impacted by staff shortages.
“While we have consistently run a proactive recruitment campaign since the beginning of the year, our efforts to get drivers on the road over the past several months were hampered by an unavoidable external backlog in acquiring essential paperwork for commercial drivers,” it said.