The Supreme Court has ruled that the Welsh Government's first law was within the Welsh Assembly's legislative competence, and can go ahead.
The outcome is entirely consistent with the general thrust of the extended powers given to the Welsh ministers, by the Government of Wales Act 2006.
The Local Government Byelaws Bill was passed by the assembly in July this year. But it was blocked from becoming law by the attorney general and referred to the court.
More top news
The Welsh Conservatives say the Swansea project should go ahead despite indications the UK Government may be about to turn it down.
Road closures are in place until 3pm today as the Cardiff Triathlon gets underway in Cardiff Bay.
It is going to stay fine and dry through the night with light winds.