Restrictions on 100 buses travelling through College Green in Dublin are set to continue into next year.
Taxis are also banned from travelling southbound during rush hour, in a bid to cope with the gridlock since the Luas extension opened.
Dublin City Council has warned the measures are likely to stay in place until 2019 because oral hearings on the planned pedestrianisation of College Green went on for longer than expected.
Chair of the Transport Committee, Councillor Ciaran Cuffe, says only radical action will ease the congestion.
Mr Cuffe said: "I think we were let down by the traffic modelling which didn't show us how severe this issue would be.
"The pain will continue until we do something dramatic in the city centre and you just can't get all those cars, buses and trams into the one space."