Gardaí have issued an appeal for road users to take extra care following what has been described as an "appalling weekend" on Irish roads.
Seven people have lost their lives on the roads since Friday in a number of separate collisions.
A man in his early 20s died in a single-vehicle collision in Co Limerick at about 12.30am this morning.
The incident happened on the R512 at Carrigmartin, Ballyneety. The man was the only occupant of the vehicle and was pronounced dead at the scene.
His body has been removed to University Hospital Limerick for a post-mortem and gardaí have appealed for witnesses to contact them.
This afternoon, gardaí said there had been a worrying and rising trend in road deaths.
Assistant Commissioner Paula Hilman advised drivers to take weather conditions into account and to take breaks if they feel tired.
Speaking on RTÉ's News at One, she said it had been a "tragic" weekend.
"We should all drive within road and weather conditions," she said. "I would ask people to take that into account - not just today, but any day of the week."
Gardaí also repeated a call for people not to share images or video footage of fatal road accidents, saying this could be a "distressing" way for people to learn of the death of a loved one.
'Appalling weekend' on the roads
Two men in their 50s and 60s were killed in Dublin on Friday in a collision involving two motorcycles and a truck, while a motorcyclist in his 40s died following a crash near Clifden in Kilkenny on Saturday.
The Road Safety Authority said it had been an "appalling weekend" on Irish roads.
RSA Chairperson Liz O'Donnell said: "I think what we have to reflect on is that we are seeing an increase in fatalities in road crashes this year."
Speaking on RTÉ's Morning Ireland, she said: "That is really distressing for everyone involved in road safety."
Ms O'Donnell said the night time economy is returning and weekends are now emerging as a "very high risk time".
"Nearly half of road fatalities are happening at weekends and 32% are happening late at night - between 10pm and 8am in the morning," she added.