Gardai said they detected 322 drivers over the speed limit during an intensive 24-hour enforcement period which ended at 7am on Saturday.
During An Garda Síochána’s National Slow Down Day the speed of 176,521 vehicles was monitored.
The highest recorded speed during the 24-hour period was a learner driver detected driving at 171km/h in a 100km/h zone on the N7 in Limerick.
#Thumbsup16 DMR Traffic detect speeds up to 180kmph, Driver to be prosecuted by summons for dangerous driving pic.twitter.com/4aXQxWJn48
— An Garda Síochána (@GardaTraffic) May 27, 2016
In Co Donegal a vehicle was detected at 140km/h in a 100km/h zone in Carndonagh, Co Donegal.
A motorist was detected travelling at 121km/h at Ballynacarrow, South Ballinacarrow, in Sligo, some 70km/h over the 50km/h limit.
Slow Down Day aims to reduce the number of speed-related collisions, save lives and reduce the number of people injured in collisions.
Earlier this week, gardaí revealed the location of more than 330 new speed enforcement zones, bringing the national total to more than 1,000.
These zones will be monitored by privatised speed cameras operated by the GoSafe consortium.
The decision to increase the level of speeding enforcement is based on a detailed analysis of fatal, serious and minor road collision.
In Dublin, speed limits are to be reduced to 30km/h throughout the city and suburbs under proposed new bylaws from Dublin City Council.
Ten years ago the council lowered speed limits in the shopping and central business area of the city from 50km/h to 30km/h.
Review
Following an 18-month review of traffic conditions throughout the city and suburbs, and following submissions from city councillors and the public, the council plans a radical expansion of the speed limit to almost all roads and streets as far as its boundary with the four other Dublin local authorities.
The lower limit will be imposed in phases from the end of this year.
Under the first phases the limit will be extended west of the current city centre 30km/h zone to cover most of the streets between the Royal and Grand canals.
The next phase, scheduled for introduction in 2017, will cover suburbs such as Sandymount, Crumlin and Drimnagh, Raheny, and parts of Cabra, Phibsborough, Coolock, Glasnevin and Drumcondra.