A car was caught doing 110km in a 100km in County Tipperary in the first few hours of National Slow Down Day.
The motorist was clocked on the N24 at Woodroofe near Clonmel.
Within two hours of the nationwide campaign GoSafe checked the speed of 19,246 vehicles.
Of those they detected 153 travelling in excess of the applicable speed limit.
Inspector James White of Thurles Garda station is urging people to abide by speed limits.
“Since 7am this morning Gardaí are conducting Operation SlowDown for a 24 hour period.
“Today will be the final working day for the majority of the country and experience has shown us that it’s a particularly busy day on the roads between last minute shopping and people rushing to get out of the towns and cities to return home for the Christmas break.
“We’re asking people to be conscious of their speed today. Please slow down and bear in mind its estimated that 30% of fatal collisions are the result of speeding or inappropriate speed.”
