A toddler, two young friends and a man in his 50s are the latest victims to lose their lives in road traffic accidents.
The man in his 50s died in the two-vehicle crash on the N25 at Luffany, Slieverue, Mooncoin, Co Kilkenny at approximately 9.15pm last night.
The man, who was the only occupant of his car, was involved in a collision with a lorry. He was rushed to Waterford Regional Hospital where he was declared dead a short time later.
Meanwhile, Lily O'Toole, who was just 21-months-old, died when a car driven by a family friend accidentally rolled over her just outside her home on Saturday afternoon.
Neighbours in the Ard Mor Walk estate in Tallaght, west Dublin, said her mother Ruth O'Toole was absolutely "devastated".
Gardai said her death was being treated as a "tragic accident" and the vehicle was moving very slowly at the time the child was struck.
Ms O'Toole's sister, Mia Maher, told how she was "lost for words" and had been left heartbroken.
"My beautiful niece has just been taken away from us my heart is broken in a million pieces," she wrote on Facebook.
In a separate incident, two friends were killed in a road crash at Sooey, Co Sligo, on Saturday.
Declan McCormack (22), from Ballinarry, Riverstown, Co Sligo, and his passenger Owen Kelly (20), from Greaghnafarna, Dromahair, Co Leitrim, both died instantly in the incident.
It is understood that Declan, a farmer and machinist, lost control of his Toyota Starlet Glanza on the road linking Ballyfarnan and Sligo. The car struck a tree shortly before midnight.
A 21-year-old rear seat passenger was taken to Sligo General Hospital for leg injuries but his condition was not life-threatening.
Gardai have appealed for witnesses to contact Ballymote garda station on 071 9189500.
The deaths bring to 38 the number of people who have been killed on the roads this year, 14 more than the same period in 2012.
A young GAA player also died in a road collision in Northern Ireland over the weekend.
Keelen Mullan (17), from the Drumsurn area of Limavady, in Co Derry, died after the car he was driving was involved in a crash with a tractor.
The accident happened on the Drumsurn Road, near the junction with the Cloghan Road on Saturday.