The official definition of the R328 from the Roads Act 1993 (Classification of Regional Roads) Order 2006[1][2] states:
R328: Ballindine, County Mayo - Moylough, County Galway
Between its junction with N17 at Ballindine East in the county of Mayo and its junction with N63 at Moylough in the county of Galway via Irishtown in the county of Mayo: Doonmacreena Bridge at the boundary between the county of Mayo and the county of Galway: Garrafrauns; Castle Street and Barrack Street at Dunmore; Kippaunagh, Ballyedmond and Mountsilk in the county of Galway.