A garda spokesperson has urged people to call out any unsafe behaviour on the roads as An Garda Síochána's Christmas and New Year road safety campaign continues until 5 January.
Garda Superintendent Liam Geraghty said 149 drivers were arrested in the week from Monday, 22 December for driving under the influence of an intoxicant, which can be either alcohol or drugs.
So far, in the month of December that figure stands at 600 arrests, while Supt Geraghty said 43% of those tested positive for drugs, predominately cocaine and cannabis.
He said all risky and dangerous driving activity should be called out and said people who see others taking drugs or alcohol who then get behind the wheel should ask them to moderate their behaviour.
"You might actually save their lives", he said.
"Everybody has a role to play; if you know that somebody is putting themselves at risk, why wouldn't you challenge them? Why wouldn't you ask them to moderate their behaviour rather than standing beside their funeral and grieving them?"
During the fourth week of this seasonal campaign, three people died on Irish roads while there were eight serious collisions that resulted in a number of people receiving serious and life-threatening injuries.
So far this year, 189 people have died on Irish roads.
An Garda Síochána carried out over 2,100 checkpoints in the week to Sunday, 28 December where a variety of issues were found.
Some of the top speeds detected included a driver in Limerick driving at 207 km/h in a 100km/h zone, another driving at 167 km/h in an 80 km/h zone in Laois, and one driver doing 118km/h in a 50km/h on Dublin's North Circular Road.
More than 435 vehicles were seized for a range of offences under the Road Traffic Act, while 150 Fixed Charge Notices were issued for driving while using a mobile phone.
Gardaí issued 45 Fixed Charge Notices for seat belt offences.
Gardaí are appealing to drivers to take personal responsibility when driving, to slow down, take extra care and to give driving full attention.
