Three people were also killed in crashes in Counties Wicklow, Donegal and Tipperary.
A motorist was arrested on average every half an hour over the bank holiday for suspected drink or drug driving.
181 people were arrested in total for the offence over the weekend.
Three people were also killed in crashes in Counties Wicklow, Donegal and Tipperary between Friday and Monday.
Leo Leighio from the Irish Road Victims Association isn't surprised by the statistics: