A vehicle travelling at 131km/h in a 100km/h zone in Co Cavan was one of 170 vehicles detected as being over the speed limit during Operation Slowdown.
The twice-yearly event is to encourage drivers to keep to the speed limit and reduce the number of road accidents.
Since 7am, more than 80,600 vehicles have been checked by An Garda Síochána and GoSafe
Speaking on RTÉ's News at One, Garda Derek Cloughley of the Road Safety Unit said a recent study found that speed is a factor in one third of fatal collisions.
Gda Cloughley said that 900 people were detected speeding during last year’s Operation Slowdown, although overall compliance rates increase.
Gardaí have published the locations of many of the speeding checkpoint areas on its website.
Vehicle detected by Dundalk Traffic Corp at 171kph in 120— An Garda Síochána (@GardaTraffic) May 26, 2017
zone on M1 motorway while conducting speed checks as part of operation slowdown pic.twitter.com/rPipnMGOL0
Gda Cloughley said gardaí want the public to know where they are so they will slow down in high risk locations and help to reduce the number and severity of road traffic collisions.
Meanwhile, Met Éireann has issued a number of rainfall warnings across the country as heavy rain and thundery downpours are set to disrupt the recent spell of good weather.
Status Yellow warnings are in place for Leinster, Connacht, Cavan, Monaghan, Donegal, Clare, Cork, Kerry and Limerick over the next 24 hours.
Op Slowdown: Waterford Traffic: Detection of three speeding offences— An Garda Síochána (@GardaTraffic) May 26, 2017
between 7:30/8:30am. 140/126/125 in 100km/h zone. pic.twitter.com/VUwDfscvPv
CEO of the RSA Moyagh Murdock said "roads are at their most slippery when the weather breaks after a dry spell. When the weather breaks, this deposit mixes with rainwater and the road becomes hazardous.
"The resulting greasy road surface increases stopping distances and the risk of a skid. The sudden change in driving conditions can also catch drivers off guard."
Ms Murdock warned that "the expected rainfall and the condition of roads will make driving particularly hazardous as road surfaces become slippery reducing skid resistance."