Rail passengers have been asked to travel at off-peak times this weekend because of a shortage of carriages. Iarnrod Eireann says an existing shortage of carriages has been made worse by damage caused by last week's derailment in Co Roscommon.
Where possible, passengers should travel outside the normal Friday evening and Sunday evening peak hours "as capacity will be severely limited at these peak times on all services," the company says.
It asks Intercity passengers with flexible arrangements to make their outward trip this morning or tomorrow and their return trip on Sunday morning or Monday.
The rail situation is unlikely to affect road traffic today or tomorrow, according to Mr Conor Faughnan of AA Roadwatch.
People who use trains to travel to and from home at the weekends are unlikely to be car-users, he said.
There could, however, be tailbacks in some places on Sunday if people return to Dublin and other cities in family cars. New and existing roadworks will further contribute to traffic holdups this weekend.
They include, according to a list supplied by AA Roadwatch:
Athlone: There will be single-lane traffic on the eastbound carriageway of the Athlone Bypass with temporary diversions at interchanges for the next six months. Extreme care is required as there are no road markings.
Cork: Roadworks are in place at Rochestown on the Southern Carriageway of the South Ring Road/ Carrigaline Road.
Dublin: There are roadworks on the Ballymun Road north of the M50. Drivers who use this route as a short cut from the M50 to the airport are advised to avoid it for the next five weeks.
Strand Road will be closed inbound each day from 9.30 a.m. to 7.30 p.m. until the end of the month between the Merrion Gates and Newgrove Avenue.
Wexford: Wexford Bridge is closed for the next four weeks for major reconstruction and essential repairs.
Traffic can get into the town from the Enniscorthy side.