New drink driving laws come into effect this week.
The drink drive limit is being reduced to 50 milligrammes from the current limit of 80 milligrammes per 100 millilitres of blood.
The limit for learner and professional drivers is reduced to 20 milligrammes.
Drivers found to be marginally over the limit will face on-the-spot fines and three penalty points for first offence, as opposed to the current system of an automatic 12-month driving ban.
The new laws take effect from Thursday.
Transport Minister Leo Varadkar said a number of new measures are being introduced.
"We’re going to see a lot of gardaí on the roads this weekend," he said.
"We’re bringing in the new reduced alcohol limits, there will be mandatory testing for anyone who’s involved in a collision causing an injury or where the garda expects they have taken alcohol, and we’ll also be enacting a section of the legislation to close the loophole whereby people don’t bring their driving licence to court."