The cold snap that hit the country last night resulted in serious road congestion and a series of crashes on all road networks this morning.
In Antrim a man died following a one-car crash on the Randalstown Road late last night. A boy who was in the car has been taken to hospital.
There were reports of major delays on all commuter routes. Nicola Hudson of AA Roadwatch said: "There was a spate of crashes throughout the morning as a direct result of black ice, frost and snow fall."
A multi-vehicle crash at Ross Cross added to delays on the N3, and there were also reports of collisions in counties Laois and Kilkenny.
The M50 in Dublin was treated twice before 7am and there were no reports of crashes during the rush hour.
Met Éireann has forecast that the weather will remain very cold tonight with lowest temperatures ranging between plus two degrees and minus three degrees.
Tomorrow is expected to be another very cold day. Most parts will be dry with sunny spells, but outbreaks of rain or sleet will spread southwards during the day or after dark.
AA Roadwatch has advised motorists to take extra care when driving overnight and early in the morning.
