Dublin City Council is going to trial a traffic-free College Green every Sunday throughout July and August.
A proposal to turn the space into a pedestrian plaza was rejected by planning bosses last October.
In refusing permission, An Bord Pleanála agreed the overall idea would "significantly enhance" the area.
However, it argued that pedestrianisation could have a “significant and negative” impact on bus passengers, and taxis".
The planning authority also said that it had "unacceptable" safety concerns regarding cyclists, pedestrians, buses and emergency vehicles.
College Green Plaza
Richard Guiney from the business group Dublin Town said a trial could help ease concerns of local businesses.
"Big ideas should be trialled so you can have a look, and address any problems that you may have", he said.
He pointed out that trials could also save money "if the concept doesn't work".
A decision on the project suffered many delays, with An Bord Pleanála admitting it was a "highly complex and unique" case.