A car travelling at 144 kilometres an hour in a 100 zone was the biggest speeding culprit on National Slow Down Day.
The Garda initiative started this morning, with extra checkpoints in place around the country until 7am tomorrow.
The message is for drivers to reduce their speed, which is a factor in a third of road deaths.
Last year saw a record low number of fatalities on the roads.
But Derek Cloughley from the Gardai's road policing department says they can't be complacent: