Drivers are being warned to make sure they are safe to drive before getting behind the wheel today.
Gardai say 11 per cent of fatal road crashes involving drink happen the morning after a night out.
Yesterday, gardai in Sligo stopped a driver on the N4.
In the vehicle he was driving was an open bottle of whiskey.
The driver was taken to a Garda Station, where he failed an alcohol test.
Young people are the worst offenders with a third of all arrests involving people in their 20s.
Liz O’Donnell, from the Road Safety Authority, says gardai will be watching out for people who were drinking last night.