Further traffic restrictions are being considered for Dublin's College Green as the new Cross City Luas is still unable to provide a full service.
Assistant chief executive Dick Brady told a meeting of the city council that congestion is still being reported, despite the recent 20% reduction of peak morning Dublin Bus services.
He said the council will meet the National Transport Authority and Dublin Bus tomorrow to consider further measures.
Mr Brady said congestion at College Green following the introduction of the Luas Cross City had caused widespread delays with knock-on consequences for all forms of transport.
Paddy McCartan said the issue of taxis using College Green will have to be examined, but Mannix Flynn said the effect of the restrictions and congestion had been disastrous for the city.
He said that the council had failed to come up with a "safe proper plan".
The city council had hoped to have a pedestrian plaza on College Green with a ban on all east-west traffic, including buses, for the introduction of the Luas.
Although the plaza is supported by the NTA, it is opposed by Dublin Bus and city centre businesses and An Bord Pleanála is due to hold an oral hearing on the plan.
Private cars are already banned from going through on weekdays from 7am to 7pm.
Mr Brady said that council officials do not have a vendetta against drivers of private motor cars.
He said: "Our only aim is that the road space we do have is used in the most efficient manner and the best possible use to citizens of this city."
He said longer 55-metre Luas trams will start to be introduced "in the next week or two".
Councillors voted to be given a presentation on traffic at the March council meeting.