Gardaí are advising parents to allow themselves plenty of time for their journeys as traffic is expected to be heavy.
AA Roadwatch has advised motorists to be particularly vigilant on all routes close to schools.
Increased traffic volumes are expected in many parts of the country, particularly the north Dublin area, following the collapse of the rail line at Malahide ten days ago.
Iarnród Éireann is operating extra services to coincide with pupils returning to class.
In schools, pupils and teachers will be subject to hygiene controls aimed at preventing the spread of the human swine flu virus among children and staff.
The Health Service Executive has said that every effort will be made to keep schools from closing where there is an outbreak of swine flu.
While some schools re-opened last week, all primary and secondary schools will be open by the end of the week.
VEC questions gender rules
The General Secretary of the Irish Vocational Education Association has said that he intends to write to the Minister for Education to ask him to amend gender rules governing VECs.
A special meeting of Limerick City Council was held this evening as the council had elected too many women on the city's vocational education committee.
Last June, Limerick City Council elected three women on the nine member city of limerick VEC.
However, the Department of Education advised the council that the election was not in accordance with current gender regulations and that only two women could be elected to reflect ratio balance with the local authority.
After a special meeting of Limerick City council was called, Councillor Kathleen Leddin stepped down to allow a male colleague to take her position.
VEC General Secretary Michael Moriarty said that a number of VECs around the country were in a similar position and that he intends to ask Minister Batt O'Keeffe to amend the regulations.
