Car Free Day has been described as "meaningless joke" by the Dublin Cycling Campaign (DCC).
In Dublin, Merrion Square West was closed today from 7am to 7pm for a family fun day.
However, the chairman of the DCC, , Dr Mike McKillen, dismissed the move as "meaningless".
"Dublin City does not sign up because it isn't prepared to close the streets in a meaningful way. It's a joke. It's tokenism," said Dr McKillen.
A small number of Dublin Cycling Campaign members cycled from the Spire in O'Connell Street to the Department of Justice on St Stephen's Green to highlight the problem of dangerous overtaking in the city.
They said motorists should leave a distance of 1.5 metres between their vehicle and the bicycle they are overtaking.
"We don't need new laws. We just need effective and proper road traffic law enforcements," Dr McKillen said.
"We need to change the standard of Irish driving. You see totally different behaviour in the way French and German drivers interact with cyclists.
"Most drivers don't seem to understand there's an offence out there called dangerous overtaking. If drivers are skimming past us, that's dangerous overtaking."
Dr McKillen also conceded that there were some "errant cyclists" on the streets.
Meanwhile, AA Roadwatch spokesman Conor Faughnan said Car Free Day had little impact on traffic levels.
"The effect on traffic has been minimal. It's a benign idea, a well-meaning initiative. But the reality is that in Dublin you can't do without your car. We are acutely short on public transport by international standards. That's
the source of our problems, not us using out cars," he said.
"The vast majority are in their car for want of choice. Too often it's easy to assume that the people causing the problems are the people using cars, rather than caused by people not having options in terms of public
transport.
"A great many car users would gladly take a tube if there was one."
