Six men have been killed in separate road crashes in the Republic since last Friday
Three were killed in the space of 24 hours.
A musician from Co Derry was among those who died in the collisions in counties Waterford, Roscommon, Kerry, Louth, Tipperary and Limerick.
The latest deaths brings the number of people killed on the Republic's roads this year to 150.
Chris Bradley, a father-of-two from Desertmartin, died at the scene of a crash between a car and a tractor at Mooremont in Co Louth at around 2am on Saturday. He was the drummer in Irish country music star Declan Nerney's band.
A 21-year-old student also lost his life after he was killed in a hit-and-run in Limerick on Friday night.
Joe Drennan had been waiting at a bus stop in Castletroy after he had finished work at a local restaurant when he was struck and killed by a car that was in collision with another car.
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- Declan Nerney leads tributes to Derry drummer Chris Bradley following fatal road crash
Gardaí are still searching for the driver of one the cars involved.
Mr Drennan, who was from Co Laois, had been studying journalism at University of Limerick (UL) and was described as an "inspirational" student.
Just last year he was shortlisted for Student Journalist of the Year.
Dr Kathryn Hayes, head of his journalism course at UL, spoke over the weekend of the "tragic death" of Mr Drennan.
She said he was “an inspirational student and a hugely talented young journalist, who had a bright career ahead”.
“He was passionate and creative and will be sorely missed by all of us who had the pleasure of knowing and working with him,” she said.
The school of English, Irish, and Communication, extend our heartfelt sympathies to the family and friends of Joe Drennan who died tragically over the weekend. You are in our thoughts, as are our colleagues and students in @journalismatUL and the wider community in UL @UL https://t.co/uZv06NjUah
— School of Eng, Irish, & Communication (@SEIC_UL) October 16, 2023
The Republic's Minister for Further and Higher Education, Simon Harris, said in a post on X, formerly Twitter, that he was "sending my sincere sympathy and thoughts to all in @UL and to Joe’s family and friends on this devastating news".
"I know the university community is grieving & we grieve with them at this very sad & difficult time."
Three motorcyclists also died in separate road crashes.
A man in his thirties was killed after a collision involving a car in Roscommon on Saturday. The crash happened on the R357 Ballinasloe to Shannonbridge Road at Cloneish around 5.15pm.
The motorcyclist was taken Ballinasaloe Hospital, but was later pronounced dead.
Another motorcyclist, a man in his forties, was killed and a pensioner injured following a two-vehicle collision in Co Kerry on Saturday.
The crash, involving a motorcycle and a van, happened in Listowel at around 7pm.
The motorcyclist was pronounced dead at the scene.
A man in his seventies also died in a single vehicle collision involving a trike in Co Waterford on Sunday.
Gardaí said he was pronounced dead at the scene following the crash on the Chapel Road in Stradbally at around noon.
On Monday afternoon, a man in his fifties died following a collision between a car and a truck on the N62 at Templemore, Co Tipperary. The man, who was the driver of the car, was fatally injured, while the truck driver was uninjured.
A total of 201 people have died on roads across the island of Ireland this year, official figures from both sides of the border have shown.