A range of restrictions are in effect after the entire country was moved to Level 3 of the plan for Living with Covid-19.
The measures came into force at midnight as part of the efforts to curtail the recent rise in cases of the virus.
Thousands of gardaí are manning hundreds of checkpoints as part of Operation Fanacht, which was set up to police the Level 3 restrictions.
Checkpoints have been set up in regionally and on all the main arterial routes around Dublin to encourage people to remain in their own counties and to only undertake essential journeys.
Around 7,000 people leave Portlaoise every day for Dublin, another 2,500 depart from Gorey. Those on educational and essential journeys are entitled to travel but with traffic levels having risen last week to 80% of the pre-Covid levels, Operation Fanacht is now under way to reduce the numbers on the roads.
132 checkpoints have been set up across the country and will remain for the duration of the policing operation, which also includes high visibility and mobile patrols.
Static checkpoints are in place this morning on the outskirts of Dublin at Balbriggan, Finglas, Blackchurch and the Blessington road - but on the outbound roads to avoid major tailbacks.
Even though they do not have the legal power to stop people breaking the Level 3 restrictions, traffic will be delayed as gardaí question motorists and assess whose journey is essential and who is to be asked to turn back.
However, Garda Commissioner Drew Harris has insisted their approach will remain community based.
Along with engaging, encouraging and explaining the public health restrictions, Mr Harris said that thousands of gardaí are also available to offer support, reassurance and assistance to the elderly, the vulnerable, those living alone or anyone who needs help.
The Level 3 restrictions will remain in place until midnight on 27 October, at which point the situation will be reviewed by the Government, based on public health advice.
Chief Medical Officer Dr Tony Holohan said a broad societal effort over the coming weeks is now essential and every one has the power to interrupt the spread of Covid-19.
Minister for Health Stephen Donnelly said while the move to Level 3 will be a deeply difficult thing for people to do, if the measures are fully embraced the virus can be suppressed and pushed back.
Yesterday, the Department of Health was notified of 432 new cases and one additional death.
It brings the total number of deaths here to 1,811, while there has now been a total of 38,973 cases.
Additional reporting Fergal O'Brien
