Speed limits of 30kph will be expanded to more areas in the city this year in a move that will cost Dublin City Council (DCC) €400,000.
The Special Speed Limit Bye-Laws 2019 were adopted in full by DCC on Monday following a public consultation that showed an overall majority in favour of the proposal.
It is envisaged that the 30kph limit will be rolled out in "all residential areas" across the local authority.
The latest expansion will be introduced in three phases from March. Parts of Ashtown, Finglas, Glasnevin, Drumcondra, Ballymun, Whitehall, Santry, Beaumont, Donnycarney, Kilmore and Darndale will soon be affected.
Motorists living in parts of Ballyfermot, Inchicore, Bluebell, Terenure, Rathgar, Clonskeagh, Donnybrook and Ringsend will also be obliged to reduce their speed.
For more than a decade, the council has gradually been reducing the speed limits on its roads throughout the city and suburbs.
In 2011, 30kph speed limits were extended as far as Bolton Street to St Stephen's Green and from Church Street to Gardiner Street and Dawson Street.
Ballsbridge, Ringsend and Marino also had speed limits reduced.
In 2018, DCC stretched the 30kph limit to 19 more northside residential areas and 12 more on the southside.
According to the council's transport report, this is likely to reduce the number of fatal and serious road collisions.
"From our examination of international experiences and from an assessment of the existing 30kph speed limit areas in Dublin city, all have recorded only positive outcomes in terms of this road safety objective," it said.
"Other environmental benefits have also been recorded, such as positive feedback from residents who live within a designated 30kph area, and their continued support for 30kph speed limits post-introduction."
The council received 911 submissions from the public, 704 expressing support for the proposal and 207 opposing it.
DCC believes the total cost for the fourth phase of the 30kph expansion will be around €400,000.
"In preparing the cost estimate, we have endeavoured to ensure existing signage poles are utilised where appropriately located to minimise costs," it added.
Fine Gael councillor Ray McAdam said he favours the expansion, but stressed it needs to be policed.
"If these new slow zones can save lives, they can only be a good thing, but they will only work if gardai enforce the law," he said.