Civil defence fire tenders are being used to seal off streets where large crowds gather for parades and other celebrations.
The new counter-terrorism measure has been approved by senior Garda officers following a number of trial runs at major social events in recent weeks.
The use of special barriers and bollards, capable of withstanding direct impacts and prevent a lorry from hitting the intended target, is also likely to be extended in the coming months.
The move is aimed at preventing an attack here similar to the recent terrorist incidents in Westminster in central London in March, and in the Swedish capital Stockholm earlier this month.
Counter terrorism planning and co-ordination by gardaí, the Defence Forces and other agencies has been stepped up since the Paris terror attacks in 2015.
Gardaí and the military are now working hand-in-hand and have held several joint security planning exercises since then.
But anti-terror chiefs at Garda headquarters have also been studying a series of options on how to handle the so-called "lone wolf" attacks in which one man, with no obvious direct jihadi links apart from being radicalised either through online or social inter-actions, selects random targets.
Even prior to the Westminster and Stockholm incidents, members of the crime and security section and senior Garda officers in Dublin have been examining their options for thwarting vehicle attacks.
They began trials around St Patrick's Day, using civil defence fire tenders to seal off streets where large crowds had gathered, and these were repeated over the Easter weekend.
The use of special barriers and bollards, capable of withstanding direct impacts and prevent a lorry from hitting the intended target, is likely to be extended in the coming months.
One senior officer explained: "We are looking at measures that will not hinder the free movement of pedestrians, particularly where they are massed on the streets to enjoy themselves, but would stop a speeding lorry."
Temporary road barriers, comprised or large reinforced concrete blocks, can be erected within hours for public events and can be securely anchored into the ground without causing permanent damage.
Gardaí are also looking at other measures such as a series of complex chicanes, to slow down a lorry attacker and force him to abandon his plans.
Officers have been consulting colleagues in other countries on the tactics they have adopted for political summits and party conferences and the United States, the UK and Israel are all well advanced in the use of what is known as "street furniture" to thwart terror attacks.
In the UK, police have been consulting with architects, engineers and representatives of potential key targets - such as football stadia - to help reduce the risk of vehicle attacks at crowded locations.
Recently built locations, such as Arsenal's Emirates stadium in north London, have built barriers into the streetscape to withstand the impact of heavy lorries.
At the Emirates the giant letters spelling out the club name can also be used as a shield to stop a lorry by absorbing the collision and smashing the vehicle.
Meanwhile, elite units from the Garda and the Defence Forces have been taking part in inter-agency training on how to combat a terrorist attack, ranging from tabletop exercises to on-the-ground courses on issues such as threat assessment, display of weaponry likely to be used, evacuation of buildings and how to deal with improvised devices as well as examining case studies.
The threat level here remains at moderate, which means that a terrorist attack is possible but is not considered likely.