Garda figures show four people were killed on the roads over the bank holiday.
A motorist in Co. Louth was caught doing 203 kilometres an hour on the M1 at the weekend.
While in Kilkenny, Gardai caught a motorist travelling at 151 kilometres an hour, in an area where the signposted limit is 50.
There were 160 suspected offences for driving under the influence.
105 were for drink driving and 55 for suspected drug driving