An Bord Pleanála has given the go-ahead to South Dublin County Council for a ring road in west Dublin which opponents claim will be used by motorists to by-pass the M50.
Approval to build the second phase of the Lucan Outer Ring Road will not give rise to "significant adverse effects" on the environment, the board said.
The approval was granted subject to six conditions. Among the conditions are the inclusion of barriers and other noise-mitigation measures in the design of the road, as well as a pedestrian crossing.
There are conditions on road signage designed to ensure it is not used by long-distance traffic as an alternative to the M50.
Local Independent county councillor Mr Derek Keating said the outcome was disappointing, as the road would impinge massively on "the heartland" of residential housing in Lucan.
The proposed road, which links the Adamstown roundabout with the N4, was the subject of a lengthy Bord Pleanála oral hearing held in Celbridge last March.
The first phase of the Outer Ring Road, a 6.2 km stretch from Adamstown to Kingswood on the Naas Road, is already under construction.
The third and final stretch, which will link the Naas Road with the Tallaght Bypass on the N81, is in the early planning stages.
