Drivers using motorways in and out of Dublin are being warned of new so-called "mega" checkpoints.
They'll appear on a number of roads between now and Christmas.
At least one person was arrested during a multi-unit operation on the M1 in Dublin this afternoon.
Local officers were backed up by armed detectives, the dog unit and the Garda helicopter.
They were targeting drink driving, tax and insurance - as well as drugs and guns and criminal gangs.
Assistant Commissioner John Twomey says some gangs are using the motorway network as a means of escape.
The initiative was partly-triggered by a rise in the number of people being killed on the roads.
177 people have lost their lives on Irish roads so far this year.