The south end of Green Street will be one-way permanently.
Traffic will only be able to travel from Havre des Pas to the roundabout, and not in the opposite direction after St Helier Deputy Russell Labey won a States vote 28-19.
He says the changes will 'put residents before commuters' and the area has been a problem for too long:
"The situation that the families living on the street, in that area where it pinches, has been absolutely dreadful. Not just for the five years I've been a Deputy and they've been talking about it. But for five years before that, and before that."
The Infrastructure Minister, who opposed the idea, now has to work to deliver the changes.
The proposed restrictions will be familiar to St Helier residents, with the part of Green Street due to be closed already shut for several weeks because of roadworks.