Irish Rail is apologising to four passengers for the lack of social distancing provided in a taxi transfer from Roscommon train station.
A signal failure forced a delay of over an hour and a half on the Dublin to Westport service on Sunday.
The 10 passengers on board were offered road transfers.
Only four passengers opted for the transfer but were directed into just one taxi for their onward journey.
Irish Rail spokesperson Jane Creegan says it was unacceptable and says there are new protocols in place from today.