Private cars in Dublin city centre may no longer turn left from Westland Row into Pearse Street in Dublin 2.
Vehicles other than buses and bikes must instead turn right, with a new two-way system between Pearse Street and Sandwith Street Lower.
Dublin City Council's Claire French said that the measures would help prepare for future transport projects and would prioritise public transport and BusConnects.
She added that the number of private cars in the city centre had been reduced by 6,000 a day.
Pearse Street would be reassigned for walking, cycling, and green areas, French said.
Planned transport projects such as DART Plus and Metro North would bring many more pedestrians into the areas, she added.