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 this 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 today that it's been working hard to fix software problems that have coincided with serious driver shortages.
The company says it resulted in some trips being cancelled, which should be removed from the real-time system but in some cases, it says this wasn't happening.
The Irish Times reports a new process is being put in place to address the problem.
Dublin Bus says despite hiring an extra 290 drivers this year, it's not keeping pace with the rate the network is expanding.
Go Ahead says it's also been hit with staff shortages and that efforts to get new drivers on the road have been hampered by a backlog in getting essential paperwork.