It's a terrible layout, in fairness. Par for the course around that neck of the woods though. The lane markings around the city centre are absolutely atrocious, for the most part. I actually have been meaning to ask what others think of the junction beside Busáras/Customs House when heading Northbound, as the amount of near-misses I've seen here is staggering.
So, 3 lanes (ABC) turns into into 4 (1234) when you get around the corner.
To my mind:
A = 1
B = 2 OR 3
C = 4
The amount of times I've seen A going into 2 or 3 is ridiculous.
Or C going into 2 is another mad move. I'd be interested to hear others' thoughts and opinions, though.
The problems actually start back on Pearse Street/Tara Street, where two lanes become four, but one of them is right turn only. They become two lanes again as you cross the Liffey and stay right for Amiens Street. Then, under the railway bridge, they turn into your A, B, C as above. I now always take the rightmost lane, and stay in B as the extra lane C comes into existence on my right, and, to be safe, indicate left as I approach the second junction.
With current low traffic volumes, it's not too bad once you're assertive and aware of your surroundings. I found it a lot worse on the rare occasions I drove that way in BC rush hours.