Reducing speed limits to 30km/h had "only positive outcomes" for road safety, Dublin City Council's senior engineers have said.
The results of a public consultation process on plans to cut speeds on arterial routes into the city found 46 per cent were opposed to the move.
Councillors will be asked next week if they want to continue with the expansion of 30km zones or retain current limits.
A 30km/h limit already applies in almost all parts of the city. However, the council proposed extending this limit to the main traffic routes, excluding just a handful of roads.
"It should be noted that the vast majority of arterial roads in Dublin are in fact residential also," a report from city engineer John Flanagan and Brendan O'Brien, the council's head of traffic said.
As most roads were already at 30 km/h “it was now more appropriate that the default speed limit for Dublin City should be 30 km/h with specific posted exceptions to this default. This would provide better clarity to motorists and allow for significant reduction in the number of poles and signage required for the speed limits.”
Of 4,629 people who responded to the public consultation last month, 46 per cent were against the principle of expanding the 30 km/h speed limit, 41 per cent were in favour and nine per cent were in support “in principle” of the limit “with some exceptions”.
“The results from the non-statutory consultation show that there is not clear consensus from the public on the merits of extending the 30 km/h to the arterial roads in the city,” the report said.
“Some sections of these arterial roads may have features which better lend themselves to 30 km/h and at other locations the current speed limit may be felt to be more appropriate.”
Concerns had been raised that the lower limits might slow buses, but the report said Dublin Bus had made a submission stating it was "not opposed to the proposal".
The “overriding principle that must inform any decision to change a default speed limit should be road safety” the report said.
“From our examination of international experiences and from an assessment of the existing 30km/h speed limit areas in Dublin City, all have recorded only positive outcomes in terms of this road safety objective.”
Public consultation was held on the proposal last year and 56 per cent opposed to the introduction of the 30km limit. Councillors subsequently asked for a 40km limit to be introduced on some roads.
Green Party councillor Donna Cooney said road safety was "not a popularity contest" and the 30km limit should be implemented.
“This is a matter of life and death. The facts are that people are far more likely to be killed at speeds above 30km/h. We didn’t do a survey when we decided to ban smoking, we should go ahead with this because it’s the right thing to do.”