For a time the "O'Connell Street & William Street/Sarsfield Street" junction was historically an important crossroads junction in the west of Ireland with four national primary routes converging at the one place. The N7 from Dublin and the east, the N18 from Galway and the north, the N20 from Cork & Kerry and the south west and the N24 from Waterford and the south east all converged at the one place. Most of O'Connell Street was part of the N20 prior to the opening of the Limerick Southern Ring Road in 2004. It now forms part of the R527 regional road.