Up to 260 people have been arrested on suspicion of driving under the influence in the first 10 days of December.
The majority relate to drink-driving, but there have also been positive tests for drug-driving too.
The number of arrests is an increase of almost 20 on last year's figures.
Gardaí say the arrests have been made at a number of locations around the country with many taking place in the mornings and early evening.