The council were told about that many years ago. Traffic from southside coming over Collins and DeValera bridges had to go up as far as Harleys Street and across McCurtain Street because there was no right turn at the top of Mahony's Avenue. But then Harleys Street was closed (a few years ago never to reopen to traffic) and it necessitated going up to Bridge Street - all extra time, extra traffic, more fossil fuels used. It's taken the planners well over a decade to getting around to sorting this mess out. McCurtain Street itself (which used be two way and thriving) we were told was impossible to make two-way with just a single lane going west, or even a bus lane. But instead they put down footpath extensions.
Whoever the planner is for the city is most likely someone who never drove around the city centre, because they've made an absolute mess of it. People coming in from north of the city onto Leitrim Street always complained they could see exactly where they wanted to go (Patrick Street), but had to go on a world tour to get there.
Not sure why you wouldn't stay on the N20, down half moon through academy street, when you want to go to Patrick's street. Or during the day, why go to Patrick's street, there's a ban on private transport during the day there.