At least 30 Dublin bus routes are to be permanently diverted from College Green as part of new traffic plans published by the city council.
The plan which also involves a pedestrianised plaza in front of Trinity College has been put out for public consultation.
All east west traffic movements except cyclists and pedestrians will be stopped.
The plans have been drawn up following concerns about conflict points between different modes of traffic when the cross city Luas becomes operational next year.
The Luas and buses will share the two way north south route through College Green.
The city council has gone back on a plan to ban taxis and these vehicles will be allowed "unless this cause problems" according to the consultation document.
Buses travelling East on Dame St will have a faculty to turn around just before the Bank of Ireland building.
A series of bus priority measures will also see Parliament St become two way for buses only and Capel St bridge will have a contra flow bus lane.
Private motorists will still have access to car parks but those wishing to travel through the city centre will have to use Butt Bridge at Tara St or O'Donovan Rossa Bridge at Winetavern St.
The plans are out for public consultation until 24 May.
There will also be a design competition for the new plaza involving surfacing, lighting and street furniture.
The document states that the new plaza will become the "assembly room of the city".
It is hoped to have the improvements completed by June of next year.
Dublin Chamber of Commerce has said businesses in the city centre will need more detail of the potential impact of the changes.
Businesses will meet with Dublin City Council at the Dublin Chamber's offices later this week to discuss the potential knock-on effects of the plan.