Tram tests are taking place on the new Luas Cross City line through Dublin city on Friday.
People are being advised to take extra care along the route - which runs from St Stephen's Green along Dawson Street and into College Green.
<blockquote class="twitter-video" data-lang="en"><p lang="en" dir="ltr">Tram testing through College Green today <a href="https://t.co/2JiP8OUUYw">pic.twitter.com/2JiP8OUUYw</a></p>— Luas Cross City (@LuasCrossCity) <a href="https://twitter.com/LuasCrossCity/status/898508538833752064">August 18, 2017</a></blockquote>
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It comes ahead of new traffic arrangements which will come into effect from Sunday August 20th.
Dublin City Council says these changes are being introduced to coincide with the Luas Cross City tram testing, and ensure the permanent changes have time to bed down before regular daytime tram testing starts in September.
From Sunday, there will be no right turn for traffic from Bachelors Walk to O'Connell Bridge, except for buses, taxis and bicycles.
Source: Luas Cross City
Also on the north quays, there will be a new road layout from Ormond Quay Upper to Eden Quay with additional bus lanes and general traffic reduced to one lane.
New bus priority traffic signals on Bachelors Walk, approximately 100 metres before O'Connell Bridge, will control traffic flows and give priority to public transport.
On the south quays, there will be a similar new road layout from Burgh Quay to Essex Quay, again with additional bus lanes and general traffic reduced to one lane.
Brendan O'Brien is head of technical services for transport on Dublin City Council.
"The additional bus lanes will alleviate the difficulties faced by public transport on the quays, where the worst delays for buses in the city are experienced.
"At the peak morning time of 8.00am to 9.00am, over 7,000 people travel along the north quays on buses. This compares to round 500 cars and the same number of cyclists".