PATRICK Street is to close to all northbound traffic for July and August for major resurfacing and maintenance work.
The lane closure will coincide with the permanent reversal of traffic on Castle Street.
It will be the first significant change to Cork's traffic flow as part of the long-term City Centre Movement Strategy (CCMS).
The strategy will eventually see private cars removed from Patrick Street and MacCurtain Street reverting back to two-way traffic.
The northbound lane closure will commence next Tuesday and continue until early September. All northbound traffic including buses and taxis will be diverted from Patrick Street to the quays and the South Mall.
Three bus routes will be affected The closure is required for resurfacing work to take place on the road and repairs to the stonework at the pedestrian crossings.
The maintenance work was scheduled for last year but was delayed as preparatory work was due to take place this year for the CCMS and it was decided to carry out all work at the same time to minimise disruption.
Cork City Council said the resurfacing work is taking place during the summer months when traffic volumes are reduced.
The northbound traffic was chosen for diversion as there are more options for traffic through the South Mall and along the quays and there are fewer bus routes travelling in a northbound direction.
Taxi ranks and loading bays will remain available to traffic on one side of the street, depending on the progress of the works.
When the resurfacing work is complete, traffic on Patrick Street will resume as normal. The plan to ban private cars from the street will not come into effect until next year.
In advance of the changes to Patrick Street, nearby Castle Street will see the permanent reversal of traffic.
It means cars cannot enter the street from Daunt Square but will instead enter from North Main Street before turning onto Cornmarket Street. That change is likely to come into effect later this week but is dependent on the weather as new road lining must be carried out in dry conditions.