Dublin Bus, Luas, and Go-Ahead were recently fined for delays and no-shows.
The National Transport Authority has apologised to passengers due to a "poor reduction in service performance" on public transport.
The apology comes as Dublin Bus, Luas, and Go-Ahead have received fines of around €5 million for delays and no-shows.
"As with many industries, bus operators have been experiencing significant challenges in recruiting qualified staff, following the return to economic activity in the aftermath of the Covid-19 pandemic," a spokesperson for NTA said.
"The bus industry has been particularly hard-hit with driver shortages as operators attempt to return to pre-pandemic levels of activity as well as deliver intended service improvements such as the BusConnects Network Redesign in Dublin.
"The National Transport Authority is in regular contact with bus operators, who are making every attempt to recruit more drivers so that all services can run as scheduled. The Authority formally meets Go-Ahead Ireland and Dublin Bus on a weekly basis to review performance, and driver recovery plans.
"Operators have undertaken extensive driver recruitment campaigns in recent months and significant numbers of additional drivers are expected to become available once their required training and tests are complete and licences are issued by the Road Safety Authority (RSA). In addition the Authority has undertaken a national advertising campaign to attract bus drivers to the industry.
"The impact of shortfalls in driver numbers is felt the most when low-frequency services are cancelled or when the first and last services of the day are cancelled. The Authority and operators have been working to ensure that such cancellations are minimised, that – where possible – consecutive low frequency services are not withdrawn, and that first and last daily services on a route operate.
"The Authority apologises to passengers for the inconvenience that the current poor reduction in service performance is causing them. Operators are forecasting significant improvements in reliability in the coming weeks and months, dependent on successful recruitment and retention of critical staff, in particular drivers."
The NTA said that the fines are due to "contractual standards for percentage of scheduled services that must be operated and the percentage of services that must operate on time."
"Contractual payment deductions apply if these standards are not met for all contracts with transport operators providing PSO services for NTA."
Transport for Ireland recently announced the addition of
two new 24-hour services for Dublin Bus.
