Four people have died in separate crashes in counties Kilkenny, Dublin, Cavan and Offaly.
A pedestrian, aged in his 20s, was stuck by a car on the Waterford Road in Kilkenny shortly before 6am.
He was taken to St Luke's Hospital where he was pronounced dead.
Earlier, a 22-year-old man died in a crash on the N7 near Rathcoole in Co Dublin.
Two other people, a 25-year-old woman who was a passenger in a car and 28-year-old man driving a second car, were injured.
All three were taken to Tallaght Hospital after the collision, which happened at about 1.15am.
Gardaí are appealing for witnesses to contact them.
In Cavan, an 18-year-old man was fatally injured in a single-vehicle crash on the N55 at Kilcogy.
A 16-year-old male passenger is in a critical condition in Cavan General Hospital.
The crash happened just after midnight. It is believed the car crashed into a wall as it left the main road.
Meanwhile, a woman died in a two-vehicle crash at Kennedy's Cross on the Birr to Tullamore road in Co Offaly at around 10.30pm yesterday.
It is believed a car and a bus were involved in the collision.
The four deaths bring to 163 the number of people killed on the roads so far this year, which is 22 less than this time last year.
