The 418 arrests made over the weekend for suspected drink- driving were more than predicted by the Garda.
On Friday, Assistant Garda Commissioner Eddie Rock predicted that there would be up to 400 arrests.
The 418 arrests, up to late yesterday afternoon, included 110 between midnight and 1pm on Sunday.
Meanwhile, there were five fatalities on Irish roads since Friday, two of which took place in the Republic and involved children.
The Oireachtas Committee on Transport, under the chairmanship of Sligo-Leitrim TD, John Ellis, will discuss road safety tomorrow.
The meeting, scheduled for some weeks, will hear from Garda Commissioner Noel Conroy and CEO of the Road Safety Authority Noel Brett.
Yesterday, Dublin North East Fianna Fáil TD Martin Brady, a member of the committee, said random breath-testing and drug- testing of drivers would be discussed.
"The hearings in the coming week are especially important in light of the tragic events that have unfolded on our roads in recent times," he said.
Mr Brady said that the "boy-racer" issue would also be discussed. "Incidents of young drivers, predominantly men, racing or 'playing chicken' in our communities are commonplace and completely unacceptable," he added.
"While progress has been made on reducing the numbers of deaths on our roads, it is a sad fact of life that there is not a community in the country which has not been affected by a tragedy on the roads."
Mr Brady added that the hearings were an important step in trying to establish why the various road safety messages were simply not getting through to so many drivers, especially young men.