Bus Éireann is advising people intending to travel this weekend on its intercity Expressway routes to avoid peak times, as currently, some services are unable to satisfy passenger demand.
Capacity on all Bus Éireann buses and coaches has been reduced by 50% to adhere to social distancing guidelines.
Expressway, therefore, has 8,000 seats available daily, compared to 16,000 before Covid-19 restrictions.
"While only 7% of our services overall have demand that exceeds capacity, the issue is more acute on certain routes," said Eleanor Farrell, Chief Commercial Officer, Bus Éireann.
"We recognise that the fact that it is a small minority of services that are oversubscribed is not much consolation for customers needing to access those routes.
"We regret the inconvenience being caused to some passengers and the challenge for our colleagues who are doing their very best to manage this situation," she continued.
Ms Farrell said drivers and inspectors are "not in a position to assess whether someone’s journey is necessary or not" and urged people to consider that a non-essential journey may prevent an essential worker reaching their place of employment, or someone attending a healthcare appointment.
She pointed to the fact that peak times have changed over the past months.
"People may not be aware that morning services are seeing less demand, with the peak now arising between 12 noon and 7pm," she said.
Bus Éireann now has live service updates on their Twitter feeds which are particularly useful to people wishing to travel from an intermediary stop.
"We have expedited online seat reservation on routes between Dublin and Belfast, Cork, Donegal and Letterkenny while holding a proportion of seats for people unable to book online.
"We are working hard to deliver this capability across the network.
"Anyone who buys a ticket online but is unable to travel due to capacity restrictions is of course entitled to travel on another service or a full refund," Ms Farrell said.