An extension of the ban on heavy goods vehicles in Dublin city could cost the council an extra €200,000 a year in rebates, according to a report on the proposal.
Five-axle trucks are currently banned from the city centre between 7am and 7pm every day and officials have been asked to extend this to midnight.
A report for the council's transport committee said such an extension would mean more refunds for hauliers forced to use the East Link bridge to travel between the south and north port areas.
The report calculates that extending the ban would involve an extra 80 trips a day on the bridge, costing the council €200,000 more a year in rebates.
It points out the East Link bridge will revert to council ownership in 2016 and that the HGV cordon could be re-examined when the future operation of the bridge is discussed.
Fine Gael councillor Gerry Breen, who proposed extending the HGV ban, said a time limit of 10pm should be considered on a trial basis, as it would make the streets calmer and facilitate the social life of the city.
The HGV ban was introduced following the opening of the Dublin Port Tunnel in 2006.
It has led to an 88% overall reduction in five-axle trucks using the city centre.
The issue will be discussed at the council transport committee meeting next week.