341 people were caught breaking the speed limit during National Slow Down Day.

The speed of 135,000 vehicles was checked for the 24-hour Garda initiative, which officially ended at 7 o'clock this morning.

The worst offenders were 3 drivers who were caught doing just under 140 kilometres per hour at locations in Dublin, Mayo and Limerick.

One of them was driving at nearly 60 kph over the speed limit.

That driver was detected doing 138 kph per hour in an 80 kilometre zone on the Belgard Road in Tallaght.

Gardaí have thanked the over 134 thousand drivers who kept within the speed limit.