The project included a 6 and half metre wide carriageway, two 2 metre wide footways and two 2 metre wide cycletracks, a new junction, landscaping, and drainage.
In their first meeting since the local elections last month, councillors representing the Naas Municipal District threw out the controversial route, which would have linked the Dublin Road with Blessington Road, by a majority of six to one.
A vote was due on the matter on the 16th of April, following a period of public consultation but councillors delayed that ballot until after the local elections.