A total of 459 people were arrested over the bank holiday weekend on suspicion of drink driving, according the Garda.
The highest number of arrests took place between midnight and 1pm on Sunday, when 110 people were detected.
However, Assistant Garda Commissioner Eddie Rock, head of the Garda Traffic Corps, said this morning the figures show that a "hardcore" of motorists were not getting the message about drink driving.
"It would be far preferable if that number [of arrests] was down and then we could say we had a far better compliance culture and people were getting the message," he told RTÉ Radio this morning.
Assistant Garda Commissioner Eddie Rock
"But unfortunately as yet the message is just not getting through."
He said there was "no doubt that people are a bit more responsible, but there is a hardcore of people out there who aren't getting the message that easily."
Two children died on the Republic's roads on Friday, and two in the North, but deaths over the weekend were lower than previous years. Last October Bank Holiday weekend, five people were killed in road crashes in the Republic, and 137 were injured. Around 324 people were arrested for drink-driving offences over the same period.
Gardaí have expanded their activities to combat drink driving since August when they were given the power to carry out random mandatory breath testing of motorists.
The measure is believed to have contributed to an immediate reduction in road deaths. There were 17 deaths in August and 23 in September. Up until 9am today, 31 people have died on the roads in October.
A total of 310 people have died in crashes so far this year, down from 322 for the same period in 2005.
This morning Assistant Commissioner Rock said he had "no doubt that people's lives have been saved" by random breath testing.
He added: "I think we're a little bit premature in detecting any specific trends. Hopefully the deaths will start to come down and that will be followed by a significant reduction in the number of arrests we have for drink driving."
He said drink driving arrests were peaking at the same time as fatal crashes were happening most frequently, between midnight and 4am. He said figures for speeding over the bank holiday weekend were not yet available.
