Dublin retailers say the new city centre traffic arrangements could lead to job losses.
From this morning, general traffic will be reduced to one lane from Ormond Quay Upper to Eden Quay on the northside, while on the other side of the Liffey, there will be just one lane for private vehicles between Burgh Quay and Essex Quay. There'll also be no right turn from Bachelors Walk to O’Connell Bridge except for buses, taxis and bicycles.
The new layout means an additional bus lane is in place on either side of the river along this stretch.
"Most of the shoppers who go city centre do use public transport but the other side of that is most of the people who travel by car actually spend more money in the city centre", says John Douglas from Mandate Trade Union.
"Those who will be possibly most affected are the people who spend most money in the city centre and if they stop coming to the city centre and choose to go to out-of-town centres, it'll have a major impact on jobs in the city centre".
Dublin City Council says the permanent changes are being made now so that they can be embedded before the Luas Cross City Line is in use later this year.